Cheap Cell Phone Jammer

Only $166. It’s the size of a cell phone, has a 5-10 meter range, and blocks GSM 850, 900, 1800, and 1900 MHz.

I want one.

Pity they’re illegal to use in the U.S.:

In the United States, United Kingdom, Australia and many other countries, blocking cell-phone services (as well as any other electronic transmissions) is against the law. In the United States, cell-phone jamming is covered under the Communications Act of 1934, which prohibits people from “willfully or maliciously interfering with the radio communications of any station licensed or authorized” to operate. In fact, the “manufacture, importation, sale or offer for sale, including advertising, of devices designed to block or jam wireless transmissions is prohibited” as well.

EDITED TO ADD (10/12): Here’s an even cheaper model. I’ve been told that Deal Extreme ships the unit with a label that says it’s a LED flashlight—with a value of HKD 45—so it will just slip through customs.

EDITED TO ADD (11/6): A video demo.

Posted on October 10, 2007 at 6:38 AM161 Comments


KJ October 10, 2007 6:53 AM

I would imagine they should be illegal for use anywhere, unless there are overriding security considerations. Afterall, telcos pay huge bucks for exclusive use of the allocated spectrum.

Neal October 10, 2007 7:05 AM

What about all these restaurants and movie theaters that block cell phones? They must be using some kind of jammer rather than shielding because they can turn it on and off. Doesn’t that mean they are violating the law?

DBH October 10, 2007 7:54 AM

These are reportedly used on private property such as movie theaters and meeting halls; usually surepticiously, but I note many times my phone mysteriously wont work until I walk outside the room…

greg October 10, 2007 8:07 AM

I would think this illegal in most countries.

With some hacking its possible to block a wide range of communication’s. ie GPS as well. often the magnetron from a microwave is used together with some nonlinear effects to get a nice wide band signal. White nosie can also be created with a small amount of high speed digital electronics. Power can be a problem however..

The catch is that you can also get located pretty quickly if you have independent units.

Sean Cleary October 10, 2007 8:19 AM

5 comments and no one has mentioned Iraq? There may be an obvious use for this technology.


Shachar Shemesh October 10, 2007 8:22 AM


That, in itself, doesn’t mean a thing. Simply decorating the walls and ceiling with conductive material will create a Faraday cage, and should achieve that same effect, and is totally legal (and pretty cheap).


John Davies October 10, 2007 8:36 AM

Never mind Iraq – I want one for my train commute. No more “I’m on the train” being bellowed into a phone. Bliss!

And if it could also render iPods inoperable then I’d pay double.

loaverman October 10, 2007 8:38 AM

These are reportedly used on private property such as movie theaters and meeting halls; usually surepticiously, but I note many times my phone mysteriously wont work until I walk outside the room…

VidKid October 10, 2007 8:45 AM

In my opinion, the Communications Act of 1934 was one of the most intelligently-written pieces of law in living memory.


Nostromo October 10, 2007 8:50 AM

Why should this be illegal if used within private property?

If it’s illegal to jam cellphones in a movie theater or a concert hall, then IMHO the law needs to be changed.

Kevin October 10, 2007 8:52 AM

Um, some people have pretty vital reasons to have cell access. People on emergency call and people waiting for transplants kinda need those pagers to work. But yeah, screw emergency need for having a quieter lunch, right?

Jo October 10, 2007 8:55 AM

This could be a really bad thing if there was an emergency of some description… imagine if there was a fire, a train derailment, a hostage situation, etc. A phone could save lives.

@John Davies October 10, 2007 8:58 AM

Now why on earth would you want to shut other people’s iPods off? iPods keep noisy people quiet.

David October 10, 2007 9:04 AM

In fact, emergency workers predate cell phones, and there were perfectly good ways of notifying them before they were expected to wear phones. In the meantime, virtually all cell phone use is for non-emergency purposes.

Why should I have to listen to somebody else’s phone conversation in the movie theater because it’s theoretically possible that there might be an emergency worker in the theater, and it’s also possible that there might be an emergency during the movie, and that that particular emergency worker is vitally needed for that particular emergency?

Besides, wouldn’t this be offset by the theoretical possibility that somebody might bring a bomb into a theater to be detonated by a cell phone? As long as we’re talking about everyday behavior being governed by long-shot odds?

Carlo Graziani October 10, 2007 9:11 AM

Well, if you’re looking for an Iraq angle, I suppose convoys could use these to suppress cell-controlled IEDs…

Sum Dum Guy October 10, 2007 9:16 AM

Agree with David – cell phones go out of range all the time anyway, depending on them to have 100% connectivity is foolish regardless of jammers or not.

Also want to point out that use of jammers in Iraq isn’t too helpful – the IED trigger can be changed from an incoming call to loss of cell-tower connectivity plus a timer. Or if that is not precise enough, an optical trigger. They already went through those rounds of escalation a few years ago.

JustSomeGuy October 10, 2007 9:18 AM

“Well, if you’re looking for an Iraq angle, I suppose convoys could use these to suppress cell-controlled IEDs…”

And then they build bombs that go off when they stop getting a signal.

And then the 30′ pole with cell phone jammer on the end becomes standard equipment.

And then they bury bombs 30′ from the ‘fake’ bomb.

Unless you’re the bomber, evolution is a real bitch.

Ed T. October 10, 2007 9:22 AM

“Why should this be illegal if used within private property?

If it’s illegal to jam cellphones in a movie theater or a concert hall, then IMHO the law needs to be changed.”

It is illegal because, when the law was written, so-called “active jamming” affected a much larger area than just a single room (or even a single building.) Even today, interference with the operation of radio transmitting equipment in licensed services (and the cell phone operator – the carrier – does have a license to operate) is generally considered a Bad Thing, and such jamming could wreak havoc for other services due to such things as harmonic interference.


clvrmnky October 10, 2007 9:31 AM

“I would imagine they should be illegal for use anywhere, unless there are overriding security considerations. Afterall, telcos pay huge bucks for exclusive use of the allocated spectrum.”

Well, it depends how you look at it. IANAL, but I do have a working knowledge of spectrum law in Canada (I’m an amateur radio geek). This would probably fall under the “using radio equipment that interferes with legal government or private use of the spectrum.”

That is, it probably isn’t illegal to own or experiment with these devices, but if the use of the equipment interferes or impacts other users of the same part of the spectrum, then those people can complain and your use can be curtailed.

It isn’t like the Spectrum Canada Mounties are going to break down your door. Your neighbours will give you dirty looks, and you will get polite by firm letters delivered to you describing exactly what you should not be doing.

Rob October 10, 2007 9:47 AM

The way forward is to integrate this capability into a device that your target market would otherwise buy. Marketing takes care of the rest.

“The potential mobile phone interference of Acme’s wide screen teevee set is an unfortunate side effect of Acme’s proprietary picture enhancement technology. We recommend proprietors of public meeting places use this Acme product cautiously with regard to the potential to interfere with mobile phones.”

paul October 10, 2007 9:49 AM

I would assume that it’s legal to forbid people from using cell phones on your property, so it’s not absolutely clear to me that you’re interfering with legal use of the radio spectrum by turning one on (albeit there might be some need for posting the property.)

Then again, I’d hate to be the defendant when the feds came after me in such a case.

Terry Cloth October 10, 2007 9:56 AM

Are schematics available? Just as illegal, but you wouldn’t have to worry about receiving suspicious packages from a certain Hong Kong company.

Could it be broken down into pieces whose functions are small enough to be obviously legal, but which you then assemble into a working unit?

Alternatively, is there a country in which this is legal? Would they be willing to remail stuff for a small fee? Then all you’d have to worry about is customs recognizing it (lowish risk?), or the Feds tracing the $ back to you (not worth their trouble?).

Is there some way to run anonymous Paypal transfers? Shouldn’t be too hard with a third-party Paypal account. They’d take your payment, turn it into cash, take their cut, deposit said cash into a different account, and pass it on to the desired recipient. Of course, this would put you under suspicion of being a Drug Lord.

I can see an opportunity for someone to set up the physical-world equivalent to Anonymizer: Packages are tougher to receive anonymously than bits, though.

John Ridley October 10, 2007 9:59 AM

Yes, there were emergency people before cell phones. It’d be cool if we went back to how things were done then; the doctor/whatever let work know where he would be. If they needed to contact him, they’d call the theater. The theater would then shut off the projector, bring up the house lights, and announce “Would Doctor Foo please report to the ticket window? There’s an emergency call for you.”

Because yeah, that’d be SO much less intrusive than a cell phone.

The real problem, of course, is that for every doctor that gets called away from dinner to do a heart transplant, there are 1000 morons taking a call instead of having a nice dinner and conversation with their companion(s).

John Ridley October 10, 2007 10:02 AM

“The potential mobile phone interference of Acme’s wide screen teevee set is an unfortunate side effect of Acme’s proprietary picture enhancement technology. We recommend proprietors of public meeting places use this Acme product cautiously with regard to the potential to interfere with mobile phones.”

Check the FCC rules. Such devices are licensed such that they are not allowed to interfere with any other device, and if they do, the owner is required to turn them off. An owner might get away with using it once. A manufacturer would never get away with selling something known to interfere seriously with communications.

Ed T. October 10, 2007 10:24 AM

Yes, it is legal to forbid the use of cell phones on your property. However, the use of active RF jamming equipment can have unintended (and possibly catastrophic) side-effects. What if the movie theater was next door to a hospital (where cell phone use is restricted because medical equipment uses frequencies in the same portion of the radio spectrum!), or if a truck full of dynamite and blasting caps happened to pass within range? Your jammer could create an IED – not good!


Colossal Squid October 10, 2007 10:49 AM

And what if that truck full of dynamite and blasting caps set fire to a bus full of orphans? And what if that flaming bus full of orphans crashed into a cattery full of fluffy kittens?
What then?

++Don October 10, 2007 10:54 AM

Are schematics available? Just as illegal…

I suspect that in the U.S., the schematics would be protected by the First Amendment. For precedent, look back to the 1990s when strong crypto could not be exported even in source code form. The courts ruled that printed source code was protected speech, even though electronically stored source code was not. This resulted in PGP being exported by printing its source code in an OCR-friendly font, exporting the paper, and then scanning it.

Anonymous October 10, 2007 10:56 AM


“In fact, emergency workers predate cell phones, and there were perfectly good ways of notifying them before they were expected to wear phones.”

You’re right. Back to the telegraph. Or better yet, smoke signals.

Just because there were ways that pre-date said use doesn’t mean they’re still in use, feasible now or better. But you can feel better that the transplant patient on a narrow window doesn’t get that organ they needed in time – your lunch won’t be interrupted by that call.

greg October 10, 2007 11:15 AM

I get sick of the “well the doctor really need his cell phone”.. or “the parents need to know there kids are all right” is bunk. What if the “doctor” already had 3 drinks… How long does it take him to get to the hospital anyway. What are all the doctors doing that are already there? What if you have a flat battery? Should changers now be provided just in case.

Cell phones are just that. A cell phone. They are not reliable in the “emergency” sense (pagers anybody). And on call dose not mean 3 seconds delay is a death. Because otherwise you would not be on call.

If being on call is so important. Don’t go to the movies etc. When I’m on call i have restrictions on how far away i can go and how much i’m allowed to drink. Thats why i’m paid to be on call.

Dam the building I’m in now has no cell phone reception at all…

Greg October 10, 2007 11:22 AM

@Shachar Shemesh

Unfortunately this does not work as easily as you might think. Once the “cage” is significantly larger than a wavelength, its not so easy to block the signal. The ground line can even act as a aerial, and improve reception!

In NZ we made a gauss cage for some instruments. The signal was reduced, but we could still make cell phone call from inside. It wasn’t until we moved it all underground that the signals got fully blocked.

TS October 10, 2007 11:30 AM

They should be illegal. Because, while I think there are times when I would like to shut someone off, I’m in general a reasonable guy. On the other hand, there are a lot of self-righteous pr*cks out there who wouldn’t give a second thought to jamming everyone all the time. I’d rather keep it out of the hands of inconsiderate morons who would block everything than have the pleasure of blocking one or two calls that really annoy me.

Matt from CT October 10, 2007 11:58 AM

1) Most medium to large cities now operate their Fire & Police on 800mhz trunked radio systems.

These jammers will also interfere with their radios when they are near you. The public safety system’s base stations and portables may or may not have enough power to overcome your jamming.

So you end up with the situation of people not turning them off because of fires, train accidents, etc and the unintended consequence is front-line firefighters and police officers working near such jammers are also jammed from using their radios to call for help or learn of detoriating conditions.

2) As for the idea of making a faraday cage around the theater, etc — in many places that is against the building code or quickly would be made against code.

In most large cities malls, high-rises, tunnels, etc where the structure is big enough to interfere with standard public safety radios, the owners are required to install leaky cable or other technologies to bring the public safety radio signals inside.

3) It’s my understanding as of last week CyrenCall has won the FCC award for building out a joint public-private partnership 3G public safety telecommunications network.

Under CyrenCall, the frequencies will be intermingled with commercial frequencies to allow better bandwidth utilization, and to help finance the system. Within the CyrenCall bandwidth, commercial services will have a lower Quality of Service so their signals can be dropped in a disaster.

The CyrenCall system will, as I understand, by 3G broadband wireless and allow for communities to both purchase service on a utility model from CyrenCall, or to build their own network. These networks will be fully interoperable along the model of roaming between cellular companies; regardless of who your “home carrier” is it will work on the local network.

Nicola October 10, 2007 12:04 PM

Here in italy they’re illegal. The specific fellony is “interruption of public service”, it’s basically the same crime for the sabotage of radio, cable, water, electricity, etc. there have been also some cases where jammers like this were used in beaches by people harassed by other one’s stereo or cell. (and the former were convicted).

Pat Cahalan October 10, 2007 12:06 PM

I’d have to read through some legalese, but if your original post is accurate, Bruce, you can just go online and buy one.

The people selling it to you are breaking the law, but I didn’t see anything in your quoted passage that says it is illegal to purchase or own such a device. It’s just illegal to use it.

Maybe we should take up a collection and get Bruce one for his birthday 🙂

David Dyer-Bennet October 10, 2007 12:14 PM

If people start jamming cell phones, I’ll have to build a jammer locator. I figure yelling “Hey everybody, here’s the guy who’s jamming your cell phone” should do the job. And I disclaim responsibility for any resulting injuries.

I have never, once, had to listen to somebody have a cell phone conversation in a movie theater when I shouldn’t (i.e. during the feature). I’ve nearly never heard a cell phone ring there*, and when I have it’s stopped quickly, sometimes followed by somebody leaving, but not by talking more than five words. If you live in an area where people actually have conversations during a movie, I suggest you work on that behavior, instead of trying to cut people off from their kids, their baby-sitters, or their jobs (meaning they can’t go to a movie when on call, they have to sit home).

  • I’m also not counting hearing a cell phone ring that’s an actual part of the movie soundtrack!

John R Campbell October 10, 2007 12:24 PM

Speaking of jamming GPS…

I sail so I have a GPS I carry around, it’s a wonderful toy… but, every time that the President (or Vice President) comes to town, the accuracy (which is usually under 20-25 feet CEP) drops… to more like 80-100 feet, so, yeah, I suspect that these folks arrange for some local way to increase the error range of GPS receivers.

What’s funny is that I noticed, when I travelled up to NYC, that, even on a ferry boat in the middle of the upper bay, that my accuracy is lousy there, too, and it takes a lot longer to “lock in”.

It’s a Garmin GPS 76, BTW.

dragonfrog October 10, 2007 12:53 PM

In response to the frequent “on call” arguments – as long as there is a large sign outside the entrance to the jammed / faraday caged building clearly warning that cellphones and pagers will not operate inside, what’s the matter?

If you’re on call and can’t be unreachable for even a couple of hours, then read the signs, and choose restaurants that don’t jam cellphones this week. It shouldn’t be that hard; these things are hardly likely to become universal.

Yes, it’s a slight additional burden, just the same way not being able to get drunk or go camping this weekend is a burden; that’s why you’re paid an oncall premium. If you’re not paid a premium, then that’s your problem and your employer’s, not mine or the theatre’s.

jdv October 10, 2007 12:57 PM

darn! In projecting forward for my soon to be driving teenager, I always thought it would be sweet to have some sort of jammer in his car to prevent him from texting while driving!

dragonfrog October 10, 2007 1:16 PM

@ David Dyer-Bennet

Recently, I overheard one side of a very amusing cellphone call during a movie feature.

A kid probably about eight or so (since when does every eight-year-old have a cellphone anyway?) received a call from his father. He then spent about five minutes, getting increasingly embarassed, trying to get his dad to hang up without being rude enough to get in trouble.

“Dad, I’m in a movie theatre.”
“No, the movie is playing now.”
“Dad, I don’t want to annoy everyone.”
“Can you please tell me this later, Dad? I’ll call as soon as the movie’s done, promise.”

I realized – it’s not the kids who don’t know how to behave with cellphones – they grew up with the things. It’s grownups, who got them thrust on them when their phone habits were firmly set around land lines.

The movie was sufficiently silly, and the call sufficiently entertaining, that I didn’t mind much. If it had been a play, I would have had a much different response.

Chris L October 10, 2007 1:17 PM

Anyone else find it ironic that the cell phone costs less than the device to stop it from working?

UNTER October 10, 2007 1:27 PM


It’s not the receivers, it’s the transmitters which have the error on their heartbeat increased, I believe.

Throught the 90s, 30-100m was the standard error set. Under Clinton, the error was shrunk (but still larger than the technical limit), with the addition of finer grained control over the error coming from the satellites.

One worry was one of the movie scenarios: someone uses GPS to fly a model airplane through an open window of the White House and buzzes the Big Cheese.

Anyhow, the tech was also intended for military purposes: a finer grain approach to denying GPS to our enemies, which of course led to an upgrade in the Russian system since they suddenly discovered a lot of new clients.

jayh October 10, 2007 1:42 PM

It seems odd that some people who scream about cell phone conversations in the theater don’t seem to react the same way when the person has the same conversation with someone next to them.

In any case, the answer is to address the disruptive behavior itself (including personal conversation) rather than trash communication systems in an overarching assault.

Rich Wilson October 10, 2007 1:58 PM

@David Dyer-Bennet

I had someone take a cell phone call behind me during “The Passion of the Christ”. After it was evident that he wasn’t going to cut the call short, I turned around and asked him to. He continued. When he finally hung up, he tried to start a fight with me.

I was tempted to ask him “WTFWJD”? but decided to ignore him instead.

Kadin2048 October 10, 2007 1:59 PM

I wonder if you built a room as a Faraday cage, to prevent leaks, and then installed the jammer inside the room, so that there’s no way for the jamming signal to escape off of your property, whether it would then be legal?

I think that would satisfy the FCC. (Since, think about it, lots of devices use frequencies internally, they just don’t radiate them out into free space.)

Of course, if you have to build the shielding anyway, you might as well just make it heavy enough to stop cell phone transmissions in the first place.

TS October 10, 2007 2:30 PM


You’re missing the point. Sure, if it looks like we can ask the person to speak more quietly/end the call without them going postal on us, we would. But it seems that most of the time, you don’t because you don’t know that they won’t go postal on you.

Just like the driver who cuts you off; you let them go and forget about it or you risk them pulling a gun and taking a shot at you.

Anonymous October 10, 2007 2:47 PM

Whatever happened to an armed society being a polite society? Oh right, it doesn’t help much when people say polite things at your funeral.

TS October 10, 2007 2:47 PM

@Chris L
“Anyone else find it ironic that the cell phone costs less than the device to stop it from working?”

Have you tried to buy a cell phone without a contract? Without a contract, phones can easily cost a couple hundred bucks.

Anyway, defense always costs more than offense. An arrow costs $1, a suit of heavy armor costs $1000. A bullet costs $1, a bullet-proof vest costs $1000. An ICBM costs $1M, a missile defense system costs $1B and so on.

Terry Cloth October 10, 2007 3:16 PM

@TS: “Have you tried to buy a cell phone without a contract? Without a contract, phones can easily cost a couple hundred bucks.”

Actually, I buy mine in a plastic bubble at Best Buy. $70, buy minutes at any convenience store, and John Ashcroft has no idea who you are.

Movie Downloader October 10, 2007 3:21 PM

I do. Its usually the same people.

One guy just would not stop using his phone. So I took it off him, pulled that battery out and threw the whole thing to the front of the theater. Everyone else cheered. He said nothing.

Filias Cupio October 10, 2007 3:25 PM

It isn’t clear whether this is a “black hole” or a “white hole” device. (I’ve just made those terms up.)

You can make a transmitter which transmits noise at the frequency to be blocked – a white hole. Or you can make a device which pretends to be a cell base station and fools the phone into connecting to it, and then doesn’t pass any transmissions through – a black hole.

A black hole is much more neighbour-friendly than a white hole.

Erazrhead October 10, 2007 3:31 PM

Cell phones don’t annoy people, people do. Instead of trying to use the law or technology to enforce coutesy I think we should just insist on it. The sign above the entry of the theater says “Please cell phones on vibrate — No Calls in theater” If a patron cannot follow this simple request they are immediately ejected to the curb. Problem solved. Thank you.

Adrian October 10, 2007 3:31 PM

It may well be illegal in my country, but I’d be happy to carry one on my bike owing to the number of times my life is endangered by idiots who (illegally, here) use the phone while driving.

Gaius Obvious October 10, 2007 5:53 PM

@Adrian: “It may well be illegal in my country, but I’d be happy to carry one on my bike owing to the number of times my life is endangered by idiots who (illegally, here) use the phone while driving.”

Don’t you think your life would be in greater danger when the people who pass you are looking at their phone and not at you while they try to re-dial the number that was dropped when they come up behind you because you used this thing?

Leo October 10, 2007 7:29 PM

Denial of service attacks are exactly the right tool to deal with people who say or do things we don’t like. Not only should devices like this be legal and owned by all but we should also have tools on our computers to allow us to deny access to websites we don’t like. We should have tools that let us cancel the email addresses of anyone who uses email we don’t like as well.

Frieheit October 10, 2007 9:17 PM

“Cell phones don’t annoy people, people do. Instead of trying to use the law or technology to enforce coutesy I think we should just insist on it. The sign above the entry of the theater says “Please cell phones on vibrate — No Calls in theater” If a patron cannot follow this simple request they are immediately ejected to the curb. Problem solved. Thank you.”


I’m involved politically at the local level and I’ve been working with people fighting bans on things from smoking to cellphones while driving using the same premise.

I usually phrase it as “Instead of banning just start treating it like nosepicking.” I like yours better. 😀

Ronbo October 11, 2007 2:48 AM

A friend of mine has one of these, it’s terrific. We’re in a restaurant, somebody is talking loudly, he flips it on. He bought it in the UK and brought it back in his luggage (insert TSA joke here).

I want one for my daily commute, when I’m on a motorcycle rolling down the 101 with morons talking on cell phones while attempting to drive. Gee, why did they roll to the left in to my lane without looking or signaling – could it be that cell phone clutched in their left hand?

That jammer would solve the problem, disconnecting their call when I get within 25 or 30 feet of their car. Now if I only had a solution for the idiots who are glued to the rear view mirror, which is angled downwards to give them a view of the baby seat – like the strapped-in toddler is going somewhere. Aarrggghhh!

NYC Mass Trans Guy October 11, 2007 9:05 AM

@John Davies “Never mind Iraq – I want one for my train commute. No more “I’m on the train” being bellowed into a phone. Bliss!”

Hear, hear! I would buy one faster than a NY minute illegal or not just to stop these idiotic & moronic conversations that are loudly uttered on mass transit such as:



Even worse is when a person is mad about something and the “F” & “MF” bombs start flying. I often think how unfair it is that we are forced to have to listen to these idiot’s conversations when most of us would never even attempt a conversation with such people or even associate with them in the pre-cell phone world.

Still another bad example of life in the big city these days I guess. 🙁

DBH October 11, 2007 12:10 PM

Signs regarding cellphone not working aren’t needed, have you ever noticed that little bar graph on your front panel?

Matt from CT October 11, 2007 1:17 PM

In response to the frequent “on call”
arguments – as long as there is a large
sign outside the entrance to the
jammed / faraday caged building clearly
warning that cellphones and pagers will
not operate inside, what’s the matter?

Because such a technique will also interfere with legitimate use of radio systems — such as police and fire.

You will NOT see widespread adoption of such techniques, because they would be outlawed under most Fire and/or Life Safety Codes if it happened.

Rude people does not trump legitimate safety needs.

old enough to know October 11, 2007 4:37 PM

There were days when I saw “please stay off the grass” signs, no one walked on it anyway.Evolution has made people loose all decency, consideration, and intelligence. All they think about is their own life. Also in my opinion, people with Cell phones have to show the world that they are one of them ! Show offs, bullies, and complete idiots. Yes , I do own a cell phone. It is for emergencies, not “Hi, How are ya” !

2C October 11, 2007 8:05 PM

These devices have been available for years. They work. People have them, but they don’t publicize them.

Anyone who rides a commuter train into a major city every day knows how one rude person on a cell phone having a nonessential gabfest can ruin the morning for 50 others. I say “make my day.”

Simon October 12, 2007 6:51 AM

@kj “Overriding security concerns”

I’ve been told that at a NRO facility they bought thier own cell tower and keep it disconnected from the public phone system. It puts out the strongest signal and cellphones on their campus connect to it.

It’s to keep anyone who doesn’t turn off their cell phone from using them while in the building.

But what about hospitals? I’ve seen devices that detect and remind medical workers that they have their cell phones on. I presume it interferes with diagnostic and life support equipment.

Annoyed customer October 12, 2007 4:28 PM

I recently had a security system fitted. It transpires that it does not call in its presence regularly – it takes something like 2 days for the alarm company to notice that you haven’t called in. I asked the vendor (and this was a manager, not a junior minion) why wouldn’t a criminal just cut the phone wires (since they’re so easily accessible in the outside box 🙁 ) – he said that it was ‘foolproof’ because the system would call in a cut line on the cell phone backup. OK, I said, what if the criminal first sets up a cell phone jammer, then cuts the wires.

This idiot looked me straight in the eye and said “Our criminals aren’t smart enough to do that, and where would they get a cell phone jammer anyway, those things are hard to find”.

Having seen a cell phone jammer just a few days earlier (belonging, legitimately, to a security consultant who was doing expert witness work regarding it), I was not impressed by this answer.

If these things are now cheap and easy to find, expect a huge rash of burglaries once the criminals work out how stupid the majority of home alarm systems are. Even the ‘foolproof’ ones with backup cell phones :-/

RijilV October 12, 2007 5:35 PM

FWIW, the deal extreme model requires modify. There (was) a lengthy topic over on the Phone Losers of America’s web-forum about how to modify it to work for US frequencies, but eventually that thread was overrun by complete mindless idiots.

markm October 15, 2007 3:51 PM

“I asked the vendor (and this was a manager, not a junior minion) why wouldn’t a criminal just cut the phone wires (since they’re so easily accessible in the outside box 🙁 ) – he said that it was ‘foolproof’ because the system would call in a cut line on the cell phone backup.”

Ouch. I’ve worked on bank security systems that have a dedicated phone line to the police station. Cut the wires and the police get called. Short the wires and the police get called. Steal a bank end alarm module from another bank or from the manufacturer and splice it into the lines, and the “codes” the modules in the police office and the bank won’t match so the police end unit will call the cops. This system is so old that the “codes” are set by adjusting analog circuits (to vary pulse widths and relative voltages), but it works – in theory you could tap into the line with an oscilloscope, reverse engineer the codes, and breadboard a circuit to generate them, but people with the brains to learn how to do that have better ways to get rich than bank robberies.

I could cut the cost of the communication modules down to about $10 and improve the security using modern encryption for authentication techniques and microprocessors, but I think it would still be affordable only for banks, jewelers, etc. What does it cost to hold a telephone line open 24×7?

Perhaps an acceptable low-cost substitute would be an always-on internet connection, used to exchange short authenticated messages every 5 seconds. Then if two messages in a row are missing or messed up the alarm company computer tries to dial up the alarm system directly, and if it doesn’t get an answer or the answerer doesn’t authenticate, then it’s time to send security.

markm October 15, 2007 3:54 PM

OTOH, the “criminals are too stupid to use a jammer” model does work most of the time. Smart crooks get a job with their target and fiddle with the books, idiot crooks get a criminal record so the banks know not to hire them.

No Cell Movie October 16, 2007 12:36 PM

The best invention was the DVD and big screen. No cell phones, no kids, no horney teens, no idiot adults, cheap eats, pause button to go pee.

Ricardo October 17, 2007 10:21 PM

Oh I seriously HOPE that cell phone jammers become legal in the U.S. Oh what fun to shut those up around me and their pathetic ring tones!

Ravenn October 21, 2007 10:13 PM

I am a teacher in a public high school and too much of my time is taken up stopping students from texting during class, during lectures or during test. Why is it necessary for students to have cellphone access inside the classroom? Students will answer phones or make phone calls during class and the solution is to confiscate the phone. This is time consuming and I become libel for the phone. Why should I not be allowed to block the signal in the classroom?

Guitar Man October 21, 2007 10:44 PM

You all are forgetting one thing, unless someone comes with a signal receiver to test for the jamming signal, they are invisable.

All you see is no no signal bars on your phone, that happens to me dozens if not hundreds of times a day as I drive around and enter and leave buildings. Yes I drive a lot.

You will just think there is no signal, that you are in a dead spot. There is no way to tell if you are in a dead spot or a building with a jammer.

There are also static ways to block the signal and they are legal.

Just install sheidling in the walls of the building when it is under construction or remodeled.

The law that prevents “Cell Phone Jammers” prevents broadcasting a signal. It dosen’t prevent blocking a signal by setting up a physical device to prevent signals from getting in.

If you lined a room with lead, no cell phone would ever work in that room and is quite legal, expensive yes, illegal no.

One last note, these don’t cover a very large area. You need a large scanner to block the signal for 100 feet. The smaller ones only work for 8 to 10 feet, next size up only works for 15 to 20 feet. These distances are approximate.

JustShutUp October 30, 2007 3:01 PM

When cell phone users adopt a degree of etiquette, I’ll stop using my jammer.

When you travel 250,000 miles a year and have to sit next to thousands of loudmouthed, inconsiderate, oblivious people who bark into their cell phones at four times the necessary vocal volume and discuss everything from favorite shampoos to what’s for dinner, it wears you down. Cell phones are the adult busy box.

Look at people sitting in airport bars. They’re looking for something to do. So they cycle through their entire Contacts list and call everyone they know. You can’t go anywhere to get away from cell phones. Restaurants and movie theaters are no longer exempt, because the rule is no longer recognized.

Put a cell phone in someone’s hand and their manners disolve.

Jamming is the only solution for those of us who still believe that there’s a time and a place for cell phones.

Joe October 31, 2007 3:52 PM

This is for kevin from October 10th. So since we’re discussing blocking annoying superflous cell phone banter in public places I guess when we overhear that someone has called 911 and is reporting an emergency we will not block that call. How does that sound to you. A transplant…. all cell junkies might need one if the link between brain cancer and cell phone talking is created.

JustShutUp November 1, 2007 9:52 AM

It’s kind of funny how people argue about rights when few people recognize responsibility. We’re all about “I’m allowed” any more. My rights. My priviliges. But we don’t stop and think, “Is this the most responsible approach?”

The thing about blocking annoying, superfluous cell phone banter is this:

If you don’t have a signal, get up and find one. This is especially true in a restaurant or movie theater. Can’t make a call because you don’t have a signal? Well gosh, go find your signal. Get up. Get out. Talk in peace.

All you have to do is move 10 meters away from me and you’re good to go.

; )

I don’t know of a single cell phone addict who doesn’t carefully monitor their “bars.”

I look forward to the reintroduction of the phone booth. Picture a room not unlike the smoking booths we used to see in airports. A glass-enclosed, smoke-filled structure filled with choking, smoking fiends. The phone booth would be a glass-enclosed structure filled with blathering, yammering morons.

I love it.

Cell_Terminator November 4, 2007 12:51 PM

When have any of you EVER heard a physician making an important call? I haven’t. It’s always some rude ahole. If a call is an emergency the caller can go outside or away from me. Seems to me people survived on this earth before cell phones were invented. When I hear the “but…but…the doctors” I think they are the offenders making excuses to keep their public cell chatter going. Best. Invention. Ever.

bloozguy November 4, 2007 1:01 PM

I don’t buy this emergency stuff. There was a time, not so long ago,when there were no cell phones and everybody got on just fine. There are many legitimate reasons for cellphone use but I am tired of them constantly intruding on my “private” space. Jam on.

Hank November 4, 2007 2:54 PM

might be someone elses opinion but didn’t read all suggestions and comments. My take is that properties can treat cell phone usage like smoking. Post a sign that jammer is in operation. Seem legal if you notify people.

Sandra November 4, 2007 3:48 PM

Btw, I think if you’re going to use one, the best way to avoid suspicion is to to be using your own cell phone (pretending like you are talking to someone) when you turn the jammer on. Then express surprise when your fake conversation gets cut off.

Fred November 5, 2007 12:45 AM

I have worked for a 911 call center (Fire/Ambulance). I was required to carry a pager and cell phone. I took the pager to the theater, had it on hum. If a message came in, It would hum, I would read it and not disturb the person next to me (at all). I would excuse myself, leave, make a call (half the time I couldn’t get signal so call from a pay phone). Cell phone blocker? Bring it on! The pager works on a different frequency. The only disaster was me wanting to crash my cell into the head of a boob blabbing during the movie. No courtesy. Public spaces can be blabby spaces. Private spaces are private property. Want radio? Go outside. Private property should include the electromagnetic spectrum. I always heard that grounded tin foil makes a good faraday cage. Perhaps 2 grounded layers with a 3rd on the inside insulated from the other 2 and giving off a lot of white noise? That and a blocker inside, and oh, by the way, I was alive before cell phones, remember that we had emergencies back then, and am still alive, but thanks for the alarmist ‘think of the babysitter’. They can carry pagers too.

Your-physician November 5, 2007 1:22 AM


You are a major selfish clueless clod.

I can’t wait until you have some kind of surgery and then you’ll be calling your doctor at 9:35PM, when the doctor is at a restaurant that has jammed the cell phone dead, for a refill on your pain meds, because then according to your opinion there is NO important call to your physician and he/she is just an “Ahole” and thus he/she gets only worthless calls from worthless patients….like yourself.

I am a physician and I don’t make Ahole phone calls, but patients in need find me at 9:35PM, 11PM, 3AM, and you bet some of them are abusing the phone number but some are real important calls.

Just wait until you are one of those patients.

Cell_Terminator: What an Ahole you are.

PhoenixFiresky November 5, 2007 2:35 AM

Well, Your-physician, I don’t see any reason why you would have to answer a call from a patient the moment it comes in, even if you are a transplant doctor. Simple good manners would dictate that you have your phone on vibe, let it go to voice mail – and immediately leave the public area to return the call. That is the considerate thing to do, because that way only the recipient of the call is disturbed.

What I can’t stand, and nobody ever talks about, are the people who use/answer their cellphones in public restrooms. My husband works in a call center and says it’s common to get calls from people who are obviously using the toilet at the time. Not only is that disgusting, it totally violates the privacy rights of everyone else in the lavatory. I, for one, do not want to have my peeing (or worse!) broadcast over the airwaves – and I believe that I have the right to enforce my privacy in that situation. This may be a bigger problem for women than for men, as men’s hands generally tend to be occupied while they’re um…performing, but I assure you that it has happened to me more often than I can count.

In that situation, again, a call should be allowed to go unanswered and be returned when the recipient has exited the room – but apparently that’s asking too much.

I do not own a jammer, but actually am considering purchasing one for use in the scenario I described above – and only for that situation.

Robert Gammon November 5, 2007 10:10 AM

While we all get irritated at text messaging and phone calls at the cinema/theater, and we all see the risks of talking while driving, what happens when we activate one of these things and an outgoing call to 911 is blocked?

There are countless other situations in which the communications is IMPORTANT, yet all we seem to see is the TRIVIAL call (i.e. spouse/lover calls to say “I Love You”, “What’s For Dinner”), teens getting the latest gossip scoop on their pals…. ad infinitum.

We need a filter to screen the trivial from the important, and electronics does not seem to be the answer.

Alex November 5, 2007 11:46 AM

I have a pacemaker/defibrillator implant and because of this am not supposed to hold my cellphone in my left hand when using it (it’s installed just below my left collarbone). I’m not supposed to be swept with handheld wands at airports, have to be careful around store security gates in shopping centers, that sort of thing.

What happens if I’m sitting next to someone who fires off a signal from their cell phone jammer? Is there not a risk of them either triggering a defib or dumping all the data from my implanted device?

Isn’t the jammer, in EMF terms, just a high powered cell phone?

I’m a little nervous about all this. I’ll agree cell phone manners are out of hand, but a nation armed with high-powered transmitters could put me in a real jam, right?

Billy B November 5, 2007 1:27 PM

If your that worried about cell phone jammers because of the EMF effect than you should stay away from any car that have enhanced speaker systems (ie really really loud car radios). Generally the people who install them have absoultly no idea about basic electrical theory, many of those cars actually have caught fire due to the use of too small gauge wire or poor connections. Alot of these cars spew out enough radio noise that they are in effect giant EMF machines on wheels.

smartypants November 5, 2007 2:00 PM

It cracks me up to see the quotes saying “the people selling it are breaking the law.”

Nope. these are not illegal to sell. they require a slight modification to work. there are forums on this and google is your friend.

It is not illegal to sell this. it is not illegal to modify and own it — even when you modify it to work. It is illegal to use it — but for practical purposes it is IMPOSSIBLE to catch the user. run a findlaw or lexis you find no convictions.

mike November 5, 2007 2:23 PM

Jam all the phones. There are so few used for real emergencies that it is ridiculous for people to use that as an argument not to jam them.

gnfri November 5, 2007 2:31 PM

The 1934 communication act did not take into account today’s cell phone technology. it was set up for military and security reasons.
Loud, obnoxious people on cell phones in common areas should not be tolerated. It’s as if a smoker has the right to blow smoke in your face because it’s his or her’s right????????????????

Chris Claborne November 5, 2007 3:38 PM

Fun as it might be to piss someone off, aren’t you attacking the wrong problem. People just need to get a clue on how to act. Impolite to take a call during a conversation, if you do, move to a private area, if in a resturant don’t just let it ring and if you answer it, leave the area. How about address the real problem rather than being just as rude as the person we are jamming.

DB November 5, 2007 4:08 PM

Scew the laws…It’s my propertey so keep your treaspassing signals off my property. I just ordered better models and I will use them as much as I can!

Cell phone are Sh1t!

Leila November 6, 2007 8:38 AM

I know this device is illegal but it could be useful to avoid that annoying people who insists in disturbing our silence… For the ones who also liked the idea, I’ve found a video ( that shows some interesting information about cell phone jammers: its functions, how it looks like inside and the best part is an information we all want to know: how effective it is. Hmm… I liked this video, maybe these informations can be useful in the future…

Cell Me Something November 6, 2007 2:40 PM

Call me old-fashioned, but I never believed that answering rudeness with more rudeness was appropriate.

The other problem with cell-phone jammers is that they interfere with other licensed users of radio frequencies which have nothing to do with cell phones. They are wideband devices which do not confine themselves to cell phone frequencies.

Bongo November 6, 2007 6:42 PM

Simple, if there is an emergency, turn the jammer off to make the cell phone call, or use a landline, they still exist last I checked.

Janet November 8, 2007 3:15 AM

Very interesting and useful.
The study of leadership and the design of programs have not really come to grips with the rapid changes in how we interact and communicate.

Doog37 November 8, 2007 9:06 AM

Cell phone jammers are illegal for the same reasons drugs are illegal, most people are stupid and selfish and that is theway it has always been. While those who feel they would use the jammer for “good” imagine some “punk” who thinks it’s funny to walk around all day messing up peoples phone calls. This WOULD happen and the escalation that would follow would only serve to make an expensive luxury even more expensive.
With this in mind remember it is not the cell phone that magically turns people into an inconsiderate drone, they were that way before hand. In regards to the blocking in movies and restaurants I believe that if it was clearly understood that these areas do not have any reception then those “emergency” people on call should be responsible enough to refrain from being there. Sorry you took on a responsibility and I thank you for it but movies are a luxury (and I have never found cell phones a problem in a restaurant). Finally as a commuter in the NYC metro-area I have experienced many disturbances from people on cell phones but in-person conversations tend to be worse (at least on the LIRR). What is it about middle aged women that cause them to have to speak like they are in different rooms?
If you want people to be more considerate there is only two things you can do… 1. be more considerate yourself (this includes while driving also!) 2. teach you children consideration. (and while your are at it spend more time with them because this world will not get better with all of the families who spend more time with entertainment than with their children.)
However I am still self centered enough to want one, but mature enough not to get it!

marc November 9, 2007 10:40 AM

Let’s take this in increments. First, in 1934 if a person walked around in public talking to no-one they would be institutionalized. Let’s take the people with the bluetooth headsets and those with the wired ear-bud/hanging microphones and put them away.

Then, let outlaw people who walk around with their hand to their ear, let’s consider it some socialist salute. When they go to the bluetooth or ear-bud..


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ray November 10, 2007 10:46 AM

No one is interested in blocking cells that belong to people waiting for transplants or an ambulance. I am very keen to block people in my air space who insist on talking loudly about how they’re doing nothing. I’ve heard some people on cell phones….that i could not hear. This is not a difficult concept to grasp.
If we all display manners as if we are all armed; courtesy would reign.

JustShutUp November 11, 2007 9:48 PM

Looks like the votes are in. I think there are enough people out there who think “Cell Phone Jerks” are jerks.

If you’re one of them — if you set your gaudy ringtone to top volume in a public place, set your cell phone on a bar or tabletop and listen to it ring out loud while you decide whether you want to answer the call, if you’re one of those oblivious bozos who bellows obscenely while others around you look at you like you’ve had your manners surgically removed — you should feel a little ashamed. Manners still exist. The expectation of a quiet meal, an undisturbed movie and a flight or train ride without having to hear your personal barage is still high on people lists.

Find a quiet place to talk. Don’t shatter the quiet with your talk. Find a private place to converse. Don’t include others in your conversation.

A woman sat next to me in an airport bar whining and hollering about how her boyfriend was cheating on her. The conversation was embarrassingly loud. Others around me got up to leave. Others decided to stay, considering it cheap entertainment. When she was done, I said, “Sorry about your unfaithful boyfriend.”

She said, “You were listening?!?”

I said, “I was forced to. You were yelling. If you expect privacy by shouting in a public place, you’re an idiot.”

Others literally applauded.

I was in an auto-rental shuttle bus watching a woman try to wrestle two heavy bags off the bus with one hand while holding a cell phone to her ear with her other hand. She looked at a fellow standing near hear and said, “You could help me, you know, rather than just stand there.”

He said, “And you could hang up the phone, put your mind to what you’re doing, use both hands and really accomplish something.”

Again, others applauded.

Put a cell phone in someone’s hand and their IQ drops, their manners dissolve and their awareness of the many others around them disappears.

Jammers rule. They restore order where there is now nothing shy of chaos. Emergency callers find a way. Yammering morons stand helplessly silient, gazing at their lack of signal. They’re like an addict without a fix, attempting to tap a collapsed vein.

Sorry folks. We’ve put up with your loud-mouthedness long enough. Seems it’s time to fight back.

Steel yourselves for the war to come. It’s gonna be a doozey.

; )


Rob Atkins November 23, 2007 6:27 PM

Even though E-Bay isn’t allowed to sell jammers, someone was giving information as how to order one. It took me 4 weeks to get it but what a relief now when I cummute to work on the tram. As soon as I turn it on, people using their cell phone begin shaking their phone thinking they lost the signal. I have one of the higher power units and it also stops people from using their phone while driving within about 100 feet with it on the dash in the car.

Anonymous November 28, 2007 5:43 PM

i can understand movie theaters .. but restaurants? who says the people conversing at the table next to me aren’t talking too loud for me to want them to shut up? what about the people standing behind me or in front of me at the airport? yes, the ones NOT using cell phones.

there are people who talk on cell phones quieter than the people who are around you. in fact, i’d rather listen to half a conversation than to listen to both sides sometimes….

i have no qualms using my cell phone at a restaurant because 1. it’s set on vibrate.
2. i’m not talking as loud as everyone else around me because i know my mic will pic my voice up. no way in hell i’m walking outside during my meal. if someone complains, i’ll complain about them talking too loud.

boohoo November 28, 2007 5:44 PM

i can understand movie theaters .. but restaurants? who says the people conversing at the table next to me aren’t talking too loud for me to want them to shut up? what about the people sitting behind me or in front of me in an airplane? yes, the ones NOT using cell phones.

there are people who talk on cell phones quieter than the people who are around you. in fact, i’d rather listen to half a conversation than to listen to both sides sometimes….

i have no qualms using my cell phone at a restaurant because 1. it’s set on vibrate.
2. i’m not talking as loud as everyone else around me because i know my mic will pic my voice up. no way in hell i’m walking outside during my meal. if someone complains, i’ll complain about them talking too loud.

jpg November 29, 2007 4:25 AM

In France, jammers are allowed only in movie theaters.
Never minds, many thanks for the last link for a cheap jammer 🙂

GeorgiaBoy November 30, 2007 12:23 AM

As a compromise, how about using a cell jammer only when necessary? Don’t just walk around with the thing turned on, blocking all communications all the time (including that ever-present doctor waiting for the proverbial transplant call). If an obnoxious moron decides to disturb the general tranquility, THEN you can surreptitiously hit the button on your jammer for a second or two — just long enough to cause the phone call to drop. Repeat as necessary when s/he tries to reestablish contact.

Yes, this will require a bit of thought and decision making on the part of the jammer owner. Is that a necessary call? An emergency call? A doctor violating HIPAA (the patients’ federal right to privacy act) by discussing someone’s medical care in public? Is someone simply saying, “Hang on a moment while I walk outside”? If so, then don’t activate the jammer. Or is someone yelling at their spouse? Dropping the F-bomb? Working their address book for a quick hook up? Talking on and on at a restaurant, movie, opera, etc.? If so, fire up the jammer a couple of seconds for an instant moron-be-gone moment. Repeat as necessary until they get the idea that they’re going to have to go elsewhere to get “better reception.”

The selective, momentary use of a jammer makes a whole lot more sense to me than leaving it on to block everyone’s communication all the time (or driving along with a high-power jammer on your dash, disrupting the calls of everyone you pass on the street — even though they aren’t disturbing you in the least, Mr. Atkins). As an added bonus, transmitting a jamming signal in short bursts makes it almost impossible to triangulate its location.

Arty November 30, 2007 1:49 PM

The rudeness level in this country has reached the extreme: Last night about half the people in a movie theatre checked their cell phones when the movie screen message reminded them to turn the phones off!
Guess no one remembers Star Trek, from whence this all began: Commmunicators for official business/emergencies ONLY!
If you want to chat, STAY IN YOUR HOME!

jojo November 30, 2007 3:46 PM

In response to the comment that cell phones are necessary in emergency situations: No, they’re not. Remember the olden days, way back in the 1980s and 1990s, when very few people had cell phones? We managed then by using land lines. Remember when you couldn’t talk on the phone in your car and actually had to get your messages from your answering machine at home? People are ridiculous with their cell phones. Frankly, all I want for Christmas is cell phone jammer.

El Bubba November 30, 2007 3:59 PM

This has been so interesting, I’ve read all of these posts/opinions. I thought I was the only one that felt this way.
What amazes me is all this talk of doctors and emergency people. Give me a break, they’re not that important. Have you ever noticed how doctors are always introduce as “Doctor…” WTF? I should be introduced as “Mechanic…”. Believe me, I’m just as important to your life and well being 🙂
This cell phone rudeness is a strange phenomenon, new technology that drives me crazy. Maybe I’m just old but I remember a time when you just deal with an emergency and when you weren’t at work, so what?
I find most cell phone use very rude. I’ve decided that I’m going to start talking back to people on phones, answering their questions and commenting on what they have to say, in the grocery for instance…
“No, that’s too much to pay for the roast beef! Look at the Chicken Breast! Ever seen a chicken with a 44DDD? This would feed a family!”

Tony K November 30, 2007 5:55 PM

My wife is a doctor, so I’m constantly around people with that title. Makes me crazy. I have more education that virtually every one of them, but my highest degree is a Masters. When they want me to address them by their title, I ask them to address me by mine – “Master”. Makes them crazy.. 🙂

Most on-call doctors I know carry pagers and return their calls on their cell phone when convenient. Trust me, it’s not a matter of life-or-death, that’s not why they’re on call. If someone is dying the first call is NOT to the on-call doctor!

On the other hand, most of the doctor’s I know are not on-call and don’t carry a pager, but use the cell phone constantly. Being educated does not, by itself, make you a polite person.

Jammers ought to be legal on private property with a posted sign. But it would be difficult to police when the jamming signal goes off the property…

no cell phones on airplanes December 2, 2007 5:23 PM

I just wish that the airlines would ban cell phone usage altogether on airplanes. Last night I came in from Washington DC on an early evening flight. I was sitting in first class and just wanted a little peace and quiet so I could take a quick nap. The jerk sitting next to me on the plane spent at least 35 minutes all the way until the plane was about to pull away from the gate planning his motocross ride with 3 of his buddies for the next weekend. He was talking really loudly and I thought he was never going to shut up. I gave him several dirty looks and even plugged my left ear to clue him into the fact that he was talking too damn loud. What a rude jerk! To top it off, he pulled the phone out of his bag the minute we landed and resumed his loud conversations while we were taxiing to the gate and waiting to deplane.

I’m in the US and what I would like to know if whether there is any technology out there that government officials use to detect jammers. If not, I’m buying one for my next trip to the airport. I won’t use it until I get on the plane; cell phones should be banned in such tight places anyway because there are people out there who are just this rude.

Tejasman December 22, 2007 7:54 PM

For all you idiots who cant go an hour without running your mouth about nothing, a pox on you. Shut up and drive, pay the cashier or what ever other activity you are holding up with your constant talking. If i get one (Jammer) I plan on using it to get some peace and quite in the movie, resturant,book store ect!!!

karl December 26, 2007 12:02 PM

carry a small radio and when someone is talking loudly near you turn your radio on about the same volume and hold it up near your ear but pointing outwardly toward them – they will get the point or if they don’t will have a hard time hearing and the other person on the other end will get some good music instead of the blather from the cell phone abuser

fatso December 29, 2007 2:18 PM

i would love to have one, i would jam people on the bus, the cafe, library, school, stores, and the jerk that walks right behind you talking and blabbing on, i would jam all those people that don’t have the decency to talk quiet or just shut up for a moment, i’m getting one and i will have my peace and quiet once again

Darren December 30, 2007 10:51 AM

Great idea with jammers. It’s a safer way to interrupt a cell phone talker rather than direct confrontation. You never know these days what a person will do when challenged.

Doc December 30, 2007 2:11 PM

I love these comments!

As a surgeon, I don’t usually get to leave the hospital and catch a movie when on call.

And guess what – while I’m in the hospital, I have to keep my cell phone OFF.

When I’m not there, surgeries don’t stop until I return; there are other doctors just like me who work in hospitals too!

IMHO far too much value is placed on cell phone use. As someone here pointed out – it is just a telephone, not an emergency communications device. We have emergency services radio bands for this that are not jammed by these devices.

That being said, I’m all for jamming the signal of the inconsiderate social failures that spend time chatting and texting in the theater.

PARAMEDIC January 24, 2008 7:27 PM

I AM A CANADIAN paramedic, which is a little different from the states. I cant think of one situation where any emergency worker “relies” on a cellphone. That would be a terrible strategy since cell technology is unreliable at best. There are numerous other methods of communication namely radio, radio pager, dedicated internal networks, landline etc. If your emergency relies on a cell phone RETHINK YOUR STRATEGY!!

Zefi January 29, 2008 1:38 AM

I just want one to sleep at home, when a little brother idiot uses his cellphone at night past 12 and wont respond to any pounding on his door telling to stop using the cell.

The good thing is that i live on a street corner, so a small handheld jammer wont reach to other peoples house at all.

Prison Guy January 29, 2008 3:04 PM

Jammers should be standard issue for law enforcement, especially those responsible for securing the prisons. A jammer would go a long way to disrupt some of the gang activity currently going on in the prisons. Since the FCC is dragging its feet, does anyone have any good ideas to detect the phone while in use or otherwise?

badtzjack January 30, 2008 9:02 PM

hey, for those of you who don’t like the thought of jammers blocking your “conversations”, did you ever think of simply being considerate of other individuals and not use your cells where people will be disturbed? restaurants, movie theaters, plays, and such are not places to use cells, unless you have an emergency. with the exception of that and doctors, lawyers, business people, etc., most cell phone talk is just to show others “hey, look at me, i’m important, notice me, someone is talking to me!” and the other half is to deliberately annoy. in other words, “no one is going to tell me what to do”. well, guess what? you’re not important or special; your so-called “conversation” is just babble and you look pathetic seeking attention. you’re also petty trying to make others feel miserable because you’re sad as well. and i’ve seen many people that look like they’re homeless using cells (half the time they don’t have the appropiate shoes on their feet, yet they have phones.)

i mentioned consideration, but if you had any, you would not be doing in the first place! actually, this is pretty moot because you’re just going to continue being selfish, nasty, and pitiful.

LincolnS February 3, 2008 4:35 PM

I’ve found many people shout into thier cell phone because they don’t understand the technology. I like to suggest they could hear better if they shoved the phone up their ass so it would be closer to their head.

Cell Phreaker February 3, 2008 4:44 PM

BUT, BUT, ……… your NOT trying to jam a signal, you are just trying to send your own radio communication.
And, under the telephone de-regulation act you are allowed to own any piece of equipment that any of the phone companies own. You can bet they have them.
What I’d like to jam or blow out is those loud stereos that vibrate your car when they go by.

a traveller March 2, 2008 5:36 PM

My biggest beef isn’t in theaters, or restaurants, it’s next to the resort pool, or on the beach, where people are going through their contact list with the “you’ll never guess where I am” envy trip for 3 non-stop hours. People, I did not pay $5000 for this vacation to sit in your phone booth! I’d pay extra to go to a resort that has a “no cell phone” area for it’s guests.

Vince March 7, 2008 6:32 PM

I already have a “tool” for obnoxious phone users and ashholes that smoke around other people: a large, heavy baseball bat! I’m gonna clobber you!

Anonymous March 12, 2008 10:43 PM

About Iraq; Things similar to jammers were used. Instead of jamming the IED’s cellphone, they triggered all remote detonated IEDs(garage door opener, cell phone signals, etc.) and this worked well for a bit until the T’s went back to using wires.

Tom March 27, 2008 11:19 PM

I would please like to ask the following questions as it has potential to impact personal residence security. If phone lines were cut and cell phones rendered useless you can imagine the implications. Are there portable cell phone jammers that can operate from motor vehicles? If yes what is there range? Can you detect being jammed? What could be used as alternative communication? Thank You.

Radio-Dude April 3, 2008 9:47 AM

BUT, BUT, ……… your NOT trying to jam a signal, you are just trying to send your own radio communication.

BUT, BUT,………..They have a LICENSE to use that frequency and you DON’T.

Miss(Ill)Manners April 9, 2008 3:54 AM

I am willing to bet that the very same oblivious people who blab incessantly in public about their pathetic little private lives are the ones who pushed so hard to outlaw smoking even outdoors.

I am waiting for the cell jammer with an annihilate boost button for you creeps. This technological enhancement would cause your cell phone to explode in a controlled stream through your ear into your so-called brain, but be safely (to the rest of us) contained in your otherwise unoccupied skull.

Death to cell phone abusers!

You will spend as long as it takes to teach you empathy in a purgatory sleep-deprived and otherwise battered, listening endlessly to jerks go on and on about what they had for lunch.

Don’t even get me started on the idiots who drive erratically and endanger others’ lives because their cell is glued to their ear. You deserve a quick bullet between the eyes.

The laws are just catching up to the tech, but believe me, you losers will make the smokers look like model citizens when they do.

Don’t hate the cell, hate the user

ucoondogg May 3, 2008 10:36 AM

Hello: I read, alot of talk about Cell Phone Jammers, The do’s & dont’s, What about the drug dealers ? What about the drug users ? Using their cell to sell drugs, While living in a HUD Ran apartment complex, Living off your tax dollars, & Only paying $50.00 a month to live there, While HUD, Uses your tax dollars to pay the rest of the rent ! I know ! I see it all the time, & Some poor dumb Woman, Hooked on Crack-Cocain That live’s Under HUD, In these places, Only pays $25.00 a month, While some Dealer, Move in with her, Starts selling Crack, Pill’s, Etc, Making a couple thousand a month, And you tax dollars, Keeps them going, & The use of Cell phones are their way of running their business.

Jesse June 24, 2008 4:47 PM

You don’t have the right to jam any frequencies! If you don’t like people bellowing that they are just getting on or off the train….tough! Don’t like people answering phones in the theater….tough. Wacha gonna do, hu? You gonna get physical and rough people up, or something? Ya, you do irritating things too, my friend, yes you do! How about that commotion you caused when you last farted on that crowded commuter train/bus/whatever. I wish I could buy a device to shove up your ass to keep you quiet. That’s right, you heard me, fella! And you fat ass people…geez, you stink. Go to France where they love STINK…use tax payers money, too. I’m sure we all agree. Oh, ya, and smokers know where to stick their butts….in their ear! What about people who still write checks and hold up the lines at the market and then write the amount only in dollars then dig around in their purse for change! They need stupid meters soldered to their ass so we know who to avoid….

Business Owner July 10, 2008 10:41 PM

OK – here’s a totally different scenerio. I own a manufacturing company. We have employees working on a line or at a work station. There is a lot of money lost due to employees texting or talking on their cell phones during the time they are supposed to be (and being paid for) working. We have working supervisors so they cannot watch every employee for the 470 minutes they are working. 5 minutes lost per employee per day, 100 employees – you do the math. A huge loss of productivity. I’ve found no effective way of preventing employees from bringing their phones in to work with them. Don’t give me the BS about emergency calls. We’ve always routed emergency call to the appropriate people even when it’s a stated emergency and then they discuss their lunch plans. There was a time before cell phones and people DID survive ane get along just fine.

mr manners July 26, 2008 10:19 AM

Although jamming cell phones causes them to have no service, certain pre-defined zones are not blocked. By default, these zones include…

Therefore, when you use a cell phone scrambler, you don’t have to worry about putting yourself or anyone else in danger. Rather, police, fire, and EMS radio users can still communicate, but your customers won’t be disturbed by non-emergency cell phone chatter.

security guy October 14, 2008 12:53 PM

I am in the security industry and we are starting to see these jammers used to circumvent our cellular back-ups we install to counter POTS line cuts. Direct point to point analogue circuits are VERY expensive and out of reach for our typical customer. We will have VOIP real soon, but those signals have to be transmitted somehow too. If more criminals start using this jamming technology, it may be that nobodies property will be safe.

realdoc October 22, 2008 7:22 PM

I am surprised that there is not more discussion on the validity/legality of jammers in school settings. I know for a fact that many students (high school and college) actively engage in cheating by texting, calling, and photographing. The issue of cyber-bullying (often done via cell phone) is also very real, with many states legislating that school district implement anti-bullying campaigns. We should also look at the impact on a student’s education when they have the constant distraction of a cell phone that might be recieving a text or a call during class time. If there is one legitimate place to jam cell phones for a real cause, I would think that the classroom would be the place. Today’s kids have grown up with this technology and have come to assume some entitilement to use it whenever and wherever. If parents cannot or will not teach responsible use, maybe the school systems could help out by simply installing devices that negate the use of that technology in certain places. If emergencies arise that involve the students or teachers, the land-lines would still work just fine (like they have for quite some time).

kris January 14, 2009 3:11 PM

I think this kind of device should be illegal to use in US for privet purposes. this can jepordize emergancy repsonses . I also work on the phone subject so when you have a chance check out my project:

menagerie April 16, 2009 1:17 PM

Only two entries about cellphone use in school? Ah, now there’s where I wish there would be a permanent jam. Yes, students do cheat via cellphone. Anyone caught using a cellphone (texting or playing games during lecture) gets a free pass out of my room except for scheduled exams, and then I make them place everything in their pockets, or their purse, on the table in front of them. I teach at the college level, and cell phones are a problem, but not like the problems my spouse has at the high school level. He showed the other teachers where to get a cell phone blocker, so they could get some peace. All their energy was going towards controlling cell phone use. When you get a questioning look on a student’s face it has nothing to do with the subject. . . he is wondering why he can’t get a signal (I wouldn’t sell my blocker for a zillion dollars – that look is priceless).

Oh, yeah, don’t give me that BS about emergency personnel and doctors needing a phone in the ear. The person responding to being called at odd hours of the night by patients in pain was neither a doctor nor a member of a doctor’s family. All calls are shifted to an answering service, and if the caller has an emergency they are advised to call 911 or go directly to an ER. Retiring after 26yrs as an RN, I know better than to call a doctor who is off duty. Most on-call doctors are called by other doctors – not staff or patients. Calls to or concerning patients must be kept confidential; therefore, away from others who might hear. Want to make a doctor your worse nightmare? Call them when they are having a few moments of family time. The spouse will personally come to cuss you out.

Can anyone please tell me what these people are talking about, anyway, especially the blue tooth crowd? I haven’t talked to anyone that much in my entire life, and I’ve been around for a while.

John May 2, 2009 10:16 PM

I am a school teacher, I use a cell phone jammer in my classroom. It works quiet well. My students can focus better and have good grades. I would recommend it to other teaachers, too.
The company I bought it from is Infostream. I am very happy with it.

Roger May 4, 2009 7:59 AM


I hope that you are, in fact, an Infostream spammer, as I quite prefer “teaachers” who can spell.

Deadsexy June 9, 2009 12:52 PM

To answer the quetion about trackability. Yes, jammers are trackable. I’ve spent the last 20+ years working signal exploitation. If it transmits, it can be geo-located. There are no exceptions to this rule. Yes the US and most other major world governments have people like me, that can track people like you (cell and jammer users). I am all for the jammers myself. I built both a jammer and tracker unit for my truck. I have spent many a night driving around the city mapping out all the jammers. My concern is more for those driving while talking or texting on their cells. Short story, Worse misuse of a motor vehicle I’ve seen to date: This woman was styling her hair with both hands, holding the cell phone with her right shoulder and smoking a cigarette. After she drifted lazily back and forth across four lanes of end of day traffic, causing two accidents (both were drivers trying to avoid her meandering, and in turn hitting others doing the same), a fellow truck driver and myself boxed her in and forced her to the emergency lane where we confronted her while waiting for the police to arrive. She claimed she was on an “important” call and that those drivers were trying to cut her off. The only part of the phone conversation I heard as we approached her car was “…one second, these rude jerks want to waste my time”.
I had to testify in court as to what I witnessed. She got her license suspended for six months (among other things). The very next week I saw her in the same car smoking and chatting away, while driving on the highway. That is when I decided I had to take more “drastic” action. So I built my own unit. Happy jamming.

OldGuy43 June 13, 2009 6:14 PM

“I am a school teacher, I use a cell phone jammer in my classroom. It works quiet well.”

Quiet? How about quite? School teacher, huh? Probably says something about the state of the educational system.

Anyway, my granddaughter came home complaining about having trouble concentrating because the teacher was on the cell talking about what they would have for supper. Ah for the good old days.

John August 12, 2009 1:22 PM

To Roger and Oldguy43,

English is not my first language, I am Korean. I was grateful that I found something that really helped me with my classroom and wanted to express my opinion. no need to insult people. I doubt if you can write what I wrote in Korean at all.

John August 12, 2009 1:22 PM

To Roger and Oldguy43,

English is not my first language, I am Korean. I was grateful that I found something that really helped me with my classroom and wanted to express my opinion. no need to insult people. I doubt if you can write what I wrote in Korean at all.

Sharan November 18, 2009 12:01 PM

I think all the fears being expressed about patients, doctors, firefighters, police, etc. being affected by such jamming is just mindless paranoia.

Here’s how it works in practice: Let’s say I’m carrying a jammer. I’m riding in the train, and suddenly a moron standing near by starts blabbering loudly into his phone. I can very clearly make out that his conversation has nothing to do with heart attacks, doctors, strokes, etc. The whole coach can make out that much. So I activate my jammer. The moron’s connection is cut; he swears loudly in frustration. If he puts his mobile into his pocket, I turn my jammer off. If he tries to connect again, I turn the jammer on again. Off and on, off and on, usually for short durations. That’s what I’d do. Very simple.

In the meanwhile, I am also aware of whether anyone around me is collapsing from heart attack, ruptured brains, or whatever it is you hypochondriacs think is going to happen within the span of those short interruptions. If someone is gasping, “hello, hello” into a phone, that is obviously a very different matter. I have eyes and ears, and brains too, and would be perfectly aware of any emergencies around me.

I seriously doubt that there would be any doctor travelling next to me on whom some patient has a life-or-death dependence. I seriously doubt that some patient somewhere will be desperately needing to contact some doctor who just happens to be standing next to me at that very moment. Once my jammer is turned off, any such doctor will receive a “missed call” alert, and he can then easily call back that patient if he thinks that that particular patient is a serious case.

In any case, even if that doctor takes that call, I seriously doubt that he can attend to that patient over the mobile phone; neither can he break open the doors, jump off the running train and run cross-country to that patient’s home by the shortest route. Doctors don’t do that. Doctors don’t go out of their way to serve you. Doctors don’t prescribe over the phone. Doctors give priority to covering their asses first. At best the doctor will put someone else in touch with that patient. And in any case, that patient (any sensible patient) will have that doctor’s office number, and also the numbers of other doctors. Otherwise, what would happen to that patient if that doctor’s phone happened to be switched off or if the battery was dead? Doctors forget to charge their phone batteries too, don’t they? Do you think that patient would just lie down and die? Surely no patient is stupid enough to put his life on one mobile number of one particular doctor?

I don’t think doctors will be sitting in movie theatres and classical music concerts if they are expecting important calls at any moment.
So, enough of all that doctor nonsense.

Obviously, if I spot an accident, fire or other disaster around me, I would immediately switch off his jammer. It goes without saying. Just because I want to fight back at being victimised by uncouth boors does not make me stupid. And, we are talking about ranges of merely tens of metres. We are not talking about city blocks or entire cities.

Everyone has the right to defend himself when his personal space is invaded by loudmouthed boors. I defend every teacher’s right to use the jammer in the classroom if and when necessary. I seriously doubt that any student needs to be contacted with such desperate urgency which cannot wait until the breaks or the end of class. Also, any student expecting urgent calls can inform the teacher or the office beforehand, and then take the call outside the class if it does come. It’s called basic courtesy.

So, let’s not go overboard with idealistic stupidity.

Steve January 14, 2010 6:34 AM

I drive a taxi and live in the USA, I bought one from China and only activate it when someone starts yelling, swearing, yelling the N word, etc.. or has repeated calls with those annoying ringtones. I have to listen to 2 way radio for my next job and can’t afford the interruption. I’m scared that I will interfere with an emergency situation or, be detected by the passenger or police. So far so good, I tell them it’s the aluminum metal flake paint on the car and show them that even my phone doesn’t work. go figure. When they get out of the car, I turn it off, this also saves the 2-3 hour battery life.

Drew February 12, 2010 11:03 AM

I have a handheld jammer and it works great within 30′ of anyone.
Question: Has anyone gotten through TSA with one? Since they are illegal in the US, I am curious if they can see it or detect it in the xray machines.

Anonymous :) June 21, 2010 8:36 PM

Here is another great idea that someone can make happen.. Texting while driving is Killing People! All Vehicles should be a “No Text zone!” Perhaps the automobile manufacturers should take the initiative to install 900 MHz Frequency Shielding and a Low watt Frequency Detect and Jam device to Prevent Cell phone usage from inside the Car, because some folks just don’t get it! Please except this solution and make it so.. I want no personal gain form this Idea other than safety for all!
The Frequency Jam Broadcast would only need to be a Pulse broadcast active only when the frequencies have been detected and at a signal strength to inhibit the tower exchange.

Jack Off October 21, 2010 12:08 PM

I’m builting a meg-a-watt jammer that will melt cell phone in persons ear, I’m sick of a-holes that think they are just so “cool”, my jammer will be done by next years end and will be made in china.

Ryan October 23, 2010 10:32 PM

They could use them in Iraq for the bombs that are detonated by phones AND for ones that are detonated when they lose signal if they had jammers with a longer range than the bomb does. I have a $20 jammer that goes about 25 feet. One in a car wouldn’t need the battery and could be more powerful so it could go hundreds of feet.

Bindegal February 15, 2011 2:59 AM

I found this jammer to 33 usd.
i dont know the store, but i think its from china.

Where did you get yours Ryan? 20 usd is cheap.

angela robey April 26, 2011 12:30 PM

I go to edgewood high school. Our new school was just finished being built in 2011 and they put cell phone service blockers through out the whole school. I was wondering if this was illegal or not? I think they shouldnt have these kill boxes in any school out there. Its not fair to students if teachers and administrators are allowed to use their phones during school for emergency’s why cant students use their phones.

tower March 29, 2017 3:07 AM

Anyway, I think Cell Phone Jammer is kind of belonging to the grey area between legal and illegal. Though the legislation of many countries state it as illegal, it’s sometimes useful(undeniable) in some occasions such as theaters, museums, concerts and so on, where it’s necessary to disable the usage of cell phones. As for personal usage, if you bring it to use just at your own house without interfere others’ business or threat to others’ security, it’s not unreasonable.

Manjeet August 24, 2017 11:57 PM

Cell phone networks might be easily used for eavesdropping on your private conversations and even intimate encounters with someone. We have devices which can protect your private life from any third party involvement.
Wireless industry changes very quickly these days. While it develops many useful devices it also creates many threats to the privacy of every person that interacts with the industry and devices it creates. Jammer Store company does its best to provide our customers with the best devices to jam the signals of a cell phone as well as frequencies of other devices. The technology of all our cell phone jammers and cell phone blockers was developed in Sweden, it means that all our cell phone jammers for sale have the highest quality and best specifications on the market. That’s why we are not afraid to provide the 1-year warranty on our cell phone scramblers and mobile phone jamming equipment because we are absolutely sure that these devices will be used by you without any problems. So let us give you some details on possible threats and protection measures against them.
Nowadays, GPS trackers and GPS navigation systems are becoming increasingly popular. Often, customers approach us about devices called Cell Phone Jammers. These devices make GPS tracking impossible.

jammerbuy January 31, 2018 9:26 PM

These jammers are easy to access through the network. Many Asian sites offer these services, and the potential risks of customs control may hamper the parties even if the delivery time is extended. Especially because these seizures sometimes lead to arrests.

We also found that these portable wave blockers, which can also be used in the form of traditional car keys, have been placed on the UK website, without any hesitation to place important promotional offers. Only around 60 euro standard jammers. French authorities are also concerned about the spread of jammers in the Paris region and several other major cities in the country.

The only place that you need to install wi-fi and cell phone jammer is some kind of religious place, like a temple or a church, and of course, there’s a big corporation, and time is thought to be money, employees can’t use their phones, and they should be working. Mobile jammers can also be installed in major theatres, cinemas or concert halls.
The history of mobile interference.

In the years before the GSM jammer on the market, these devices were only used for defense, but it has changed, and now anyone can use these devices to protect their privacy. In fact, we have even concluded that the portable jammer (or GSM signal scrambler) is very useful, and everyone should have one.

With the development of new technology, wireless alarm system is becoming more and more popular. The only drawback is the interference that prevents them from releasing. In the face of these risks, appropriate protection measures are recommended.

aimi November 24, 2022 2:26 AM

Standing desks appear to reduce back pain, one of the most common complaints of office workers who sit all day. To determine whether standing desks could improve this condition, several studies were conducted on employees with chronic back pain. Participants reported improvements in lower back pain of up to 32% after a few weeks of using a standing desk. Another study published by the Centers for Disease Control and Prevention (CDC) found that using a sit-stand desk for just four weeks reduced upper back and neck pain by 54 percent. In addition, removing a standing desk undid some of the improvements within 2 weeks. Several studies have shown that standing desks can greatly reduce chronic back pain caused by prolonged sitting.

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