Schneier on Security

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.

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?

Neil, note that there are ways to turn electromagnetic shielding on and off - that's called active frequency selective surfaces (see http://www.ee.kent.ac.uk/research/theme_project.aspx?pid=47 for example). It's expensive though.

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...

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.

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

Sean

@DBH

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).

Shachar

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.

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...

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

V.

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.

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?

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.

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

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?

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

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.

"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.

"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.

~EdT.

"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.

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."

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.

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: http://anonymizer.com/. Packages are tougher to receive anonymously than bits, though.

@David:
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).

@Rob:
"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.

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!

~EdT.

Apparently doesn't work with CDMA.

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?

> 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.

David:

"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.

For schematics:
http://www.ladyada.net/make/wavebubble/

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...

@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.

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.

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.

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).

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 :)

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!

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.

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.

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!

@ 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.

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

@John:

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.

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.

@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.

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.

@jayh

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.

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.

@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.

@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.

@jayh
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.

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.

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.

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.

@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?

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.

"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."

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. :D

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!

The Norwegian military can take out GPS jammers with an 'inexpensive' CRV7 rocket. Guess they can take GSM jammers too if they want to. I want one!

http://www.act.nato.int/transformation/cde/white%20papers/lcpk.doc
http://64.233.183.104/search?q=cache:rzN4mM2uMskJ:www.act.nato.int/transformation/cde/white%2520papers/lcpk.doc+%22CRV7+Low+Cost+Precision+Kill%22&hl=en&ct=clnk&cd=3

@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:

"I'M ON THE BUS I'LL BE HOME IN 5 MINUTES."
"WHAT ARE WE HAVING FOR DINNER?"
"SO WHAT'S NEW?"

I feel like grabbing them by the neck and shouting "YOU JUST TOLD HIM/HER & EVERYONE ELSE ON THIS BUS THAT YOU WILL BE HOME IN 5 MINUTES YOU STUPID FRAK!"

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. :-(

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

http://www.ladyada.net/make/wavebubble/ - A design for a self tuning RF jammer

>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.

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" !

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."

@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.

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 :-/

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.

I bought a cell phone jammer from this site, very cool gadget to have.

www.infsotream.biz

sry, the site I bought the cell phone jammer from is www.infostream.biz

"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 24x7?

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.

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.

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.

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!

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?

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.

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.

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.

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.

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.

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.

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.

drudgereport had a link to a story about jammers ... I foresee a rise in sales. :-)

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.

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.

Cell_Terminator:

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.

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.

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.

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?

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.

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.

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.

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????????????????

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.

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!

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 (http://www.weshow.com/us/p/22051/cell_phone_jammer) 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...

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.

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.

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.

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!

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..

wash
rinse
repeat

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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.

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.

; )

Me

Too bad i can't Jam the phone where i really want to...

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.

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.

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.

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

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.

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!

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.

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!"
bubba

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...

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.

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!!!

I just bought one of these super cheap and it is absolutely awesome. I use it in my car all the time and have had no issues. Got mine from www.tecknogeeks.com. Probably one of the best purchases I have made this year!

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

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

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.

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.

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!!

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.

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?

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.

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.

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.

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.

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!

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.

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.

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.

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

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.

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....

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.

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

EMS
Fire
Police
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.

http://www.thesignaljammer.com/maintaining-emergency-contact-with-cell-phone-jammers.html

What about people in prison? Do they have the right to use their illegal cell phone?

http://www.cnn.com/2008/CRIME/08/18/prison.cellphones/index.html

Instead of training dogs and constantly searching for phones, just block all transmissions. People who need a phone in the prison can use a real phone line.