Schneier on Security
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June 2, 2008
The War on T-Shirts
London Heathrow security stopped someone from boarding a plane for wearing a Transformers T-shirt showing a cartoon gun.
It's easy to laugh and move on. How stupid can these people be, we wonder. But there's a more important security lesson here. Security screening is hard, and every false threat the screeners watch out for make it more likely that real threats slip through. At a party the other night, someone told me about the time he accidentally brought a large knife through airport security. The screener pulled his bag aside, searched it, and pulled out a water bottle.
It's not just the water bottles and the t-shirts and the gun jewelry -- this kind of thing actually makes us all less safe.
Posted on June 2, 2008 at 2:27 PM
• 59 Comments
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I've worn a sweatshirt with a guy on fire http://tinyurl.com/4qfdkm on it through security at BOS, SFO, OAK, LSC, SCL, etc. and I've yet to get any trouble.
(Interestingly enough, Star Simpson was wearing the same shirt but with LEDs when she was arrested at Logan... look what that got her.)
Heck. The image on his T-shirt doesn't even look like a "gun". What idiots (and I thought that TSA had a corner on that market).
That reminds me of this experiment where people focus on one thing and miss something obvious:
"...In one study, perceivers are asked to watch a video tape of a
basketball game and they are asked to count the number of times one
team takes possession of the ball [Simons & Chabris, in press]. During
the film clip, which lasts a few minutes, a person in a gorilla suit
strolls onto the center of the court, turns and faces the audience and
does a little jig. The gorilla then slowly walks off the court. The
remarkable fact is that perceivers (including this author) do not
notice the gorilla. This is an example of what has been called
The key line in one article is the last one:
"If it's offensive, we don't want other passengers upset."
Thius wasn't even portrayed as a security threat. They have a policy of forbidding offensive dress, and guns are considered offensive. I'd say "ha ha, see what happens when you don't have a written Bill or Rights", but I know better.
I think you (and quite a few others) are barking up the wrong tree here:
This is not about security. Nobody is thinking that a picture of a gun is a security threat.
It's about potentially being offensive to other passengers. Now if this picture is offensive or not is a completely different question. To some people a picture of a huge gun might be offensive or upsetting. If that's the case it _might_ (I'm not saying it is) be right to ban such a t-shirt. Same as you might ban a t-shirt of naked people having sex or a t-shirt promoting racism.
But it's not necessarily dumb and not about security.
This reminds me of the "Captain's Head" technique. Supposedly, naval architects always make the captain's head (water closet) twice the size that it should be. When the blueprints are shown to an admiral he marks it off as too big. This allows the admiral to mark off something but not something important.
In the same way, an obvious water bottle or t-shirt distracts the TSA agent from the knife or bomb.
I would have taken it off then and there and put it back on inside out.
While entering a government building recently, I had the spork I eat my lunch with confiscated temporarily. I carry it so that I don't need to use disposable cutlery in cafeterias, but it was apparently too grave a threat to permit inside (despite umbrellas and countless other more effective ah hoc weapons).
At least it was a real spork and not just a drawing.
>> In the same way, an obvious water bottle or t-shirt distracts the TSA agent from the knife or bomb.
If it was due to being offensive, then it should have been stopped at BA's checkin desk, or by the airline crew at the gate. BAA security checks should be checking security related things.
Has anyone heard of any boy scouts or members of the military being stopped for wearing merit badges, insignias or medals depicting rifles or pistols? There are many such items. What's the difference between them an a piece of jewelry or a T-shirt? I'll bet there are some corporate logos that have these symbols, too, not to mention the NRA's.
I had an artist friend who always included one piece in every show 'for the critics'. He said critics always needed something to criticize, so he'd give them one work to really hate. And he was never wrong as to which one they'd pick.
Last time I traveled w/ my son (19), he was pulled aside and heavily searched. When we got to our destination, it turned out that one of the screeners had left the screwdriver he uses to open locked bags in my son's carry-on bag.
why not just ditch security all together and hire prison inmates. That would be as baffling to my sense of logic as this stupidity.
Exact same thing happened to me flying from LHR earlier this year, with a cartoon Boba Fett (Star Wars bounty hunter) t-shirt. At least they let me just zip up my sweatshirt over it.
Security risk? Offensive? Or just contrary to some arbitrary policy...?
While traveling domestically a few years ago with a colleague, I was stopped and searched, bomb swabbed, etc., all because I had a removable floppy drive in my laptop case. Apparently when the case was laid on its side, a pair of sunglasses that were in another pocket made it appear that there was a device with "wiring" in my case as viewed through the X-ray. Finally they searched the case and realized what they were looking at.
The pathetic part is that my colleague forgot he had a large screwdriver in his laptop case and they let him through right before me. He got to sit and wait for 15 minutes while I was searched.
Dare I say it?
The T-shirt may have been "more than meets the eye!"
I found that winking at the TSA agent works. http://bobarno.com/thiefhunters/2008/05/...
I once got through with a lethal blade hidden in a ballpoint pen, a gift from a friend which I had totally forgotten about (and had no checked luggage to put it in). I went into an absolute cold sweat when I remembered it at the security point. On the other hand, I was denied a belt! It was an antique Indian silver linked thing, very expensive. Luckily, security was close to the check-in desk, and I had the time to check my roll-aboard. It might not have been so simple otherwise.
It just seem so arbitrary. I guess I see everything, being on the road 250 days a year for the past 17 years...
I am very offended when attractive females wear clothing. I know many of you are too. It's time we voice our complaints and get some... ahem... action.
You think your friend's knife story is bad? I accidentally carried a knife through airport security _over three hundred times_ after 9/11 before they finally found it, and even then it was only while they were searching for a lighter (during the period those were banned). I had left it in my laptop bag and forgotten about it until that fateful day in 2006. I fly several times per week for work, going through checkpoints at dozens of airports all over the country, and they never once saw it on an X-ray machine. But man, they can spot a 3.5oz bottle of shampoo every time!
I wonder if i will be wearing, say, Linux T-shirt and it will offend some Microsoft employee.
You people don't have a clue! The picture of a gun was obviously a trial-run by terrorists to probe security and test the response to a real gun. That man should have been arrested for committing a terrorist act.
Many soldiers in the US Army have a marksman's pin with rifles on it on their uniforms. Do they have to remove the pin? How are the security people sure that the person is really a US soldier?
You people just don't get it: The terrorists won.
Would you like to play again?
It takes a leader to set the stage for what is acceptable. Any good CEO/manager knows this.
Sadly, the current administration has encouraged this type of thought and allowed National_Security/Homeland_Security, to become a complete joke. People are thumbing their noses to security, what a potential disaster.
I can not wait until this administration leaves office. It takes a new president to stand up and say, enough of this nonsense. Strict measures are needed, but also JUDGEMENT and TOLERANCE.
The old scotch tape on the Diebold safe joke, while the safe is open and ....
It takes a leader to keep the path.
Transformers, something we take for granted, yet are very important.
If problems with confusing real gun and a painted one are solved only by banning painted guns, you are asking for troubles. Period.
'I would have taken it off then and there and put it back on inside out.'
This was the preferred solution when I was in grade school if someone came in wearing an inappropriate t-shirt.
This reminds me of the "Unix daemon T-shirt" sad-but-true story, which first appeared in rec.humor.funny in 1989. (It was also published in "Unix Review" vol 9 no 9, Sept 1991, in Rob Kolstad's "Daemons and Dragons" column, p.81-82.)
(Warning: possibly offensive to people from Texas and/or with a literal view of Christianity.)
Armin and possibly others:
It's all very well to say "the shirt wasn't a threat, it was potentially offensive to other passengers". But you know what? There is NO BASIC HUMAN RIGHT not to be offended (however badly the militantly politically-correct would like to believe there is). There is NO LINE that can be drawn between offensive and inoffensive, because humans are remarkably (one might even say pathologically) inventive and innovative when it comes to finding things to be offended by. To one of the religious-right, a shirt saying "I'm pro-choice and I vote" is probably offensive, and one with a pink triangle on it almost certainly is. To a card-carrying ACLU member, a shirt saying "I'm pro Second Amendment, and I vote", or just one with an NRA logo on it, is probably offensive. To the militantly "child-free", a shirt with a baby photo on it is offensive. The hardline fundamentalist Christian may be offended by the devout Muslim praying to Mecca, while the radical Muslim is offended that anyone in the room does NOT kneel and pray to Mecca. No matter what you restrict on the basis that someone might be offended by it, there will ALWAYS be someone who can find something to be offended about that you never for one moment dreamed anyone in their right mind could possibly take offense at.
There is literally NOTHING on this planet that is not "potentially offensive" to *someone*. EVERYTHING is "potentially offensive". (Personally, I find the TSA extremely offensive.) Banning a water bottle or a nail clipper on a flight because some paranoid imbecile is afraid it may be part of a weapon is bad enough. Trying to ban everything that might possibly offend someone is madness.
Personally, I have more than a sneaking suspicion the raging paranoia of the TSA isn't about security — well, not about _safety_, at any rate — at all. It's about getting people used to complete control. First the airports, next the trains, and after that ... workplaces? Shopping malls? Public streets? You give them an inch, they'll take a mile, then demand to know why you hate America.
That's freaking brilliant! Intentionally making a piece of artwork to get critics to leave your good stuff alone.
And transformers aren't offensive to anyone with a brain. Simple as that.
I worked security at Toronto airport in the 70's, when hijackings were just coming into their prime. We restricted small key-chain six-guns and water pistols, etc., not because they would/could be used as weapons, but because someone commenting something like" Oh, I see you brought your gun with you," in jest, could spark a panic.
Could a T-shirt with a comic gun do the same thing? I doubt it, but the solution to the problem is so simple, why not just do it and carry on your way.
1. No carry on luggage, period. You mail your luggage in advance.
2. No clothing, only paper jumpsuits and paper slippers. Government certified apparel outlets will be available at all transportation destinations. (that means no clothing that may be deemed offensive will be sold)
3. Everyone gets weighted and screened with millimeter wave scanners. The results are kept indefinitely.
4. Hand prints, voice print, a face and retinal scan, and DNA samples will be taken at all government certified transportation centers for positive identification purposes. The information will be kept indefinitely.
Don't like it, then move somewhere else. Oh, but you can only use approved transportation centers, after receiving relocation approval.
I believe this has nothing to do with security or censorship, but it's just a matter of power. Add some new rule now and then to make people know they're controlled and commanded. It's like pulling the leash a bit so the dog remembers who's the master.
The same goes with the liquid ban, which security personnel is pushing really too far. Airport security in Paris once confiscated a small jar of paté de fois gras my grandma (85 years old) was bringing home. And I read a passenger in Catania was confiscated cannoli, a typical Sicilian sweet made primarily of creamy cheese.
My favorite incident of this sort was a couple of years ago when my then 5 year old son (a reptile enthusiast) chose a rubber snake to play with on a flight to India. The security folks almost confiscated it. They let us keep it, but made my husband promise "on your honor as a gentleman" not to take it out on the plane.
It wasn't until I got back to the states that I realized that there was a movie playing in the theaters "Snakes in Planes".
Can you elaborate on why false positives make the system less likely to catch true positives ?
This is not like a medical test is it ?
It seems to have a lot to do with the psychology of the screeners.
You should check out the link Rich posted (3rd comment here). It has a pretty good explanation on why this might occur.
Since the TSA misses 80% of the test guns and bombs even when they know the test is coming, Transformer T-Shirts give them an easy win to feel good about themselves. They can add it to their list of "incidents" to point out what a terrific job they're doing at keeping terrorists, awful fashion sense, and militant elephants out of our skies. I haven't heard of a single militant elephant sighting since the TSA took over, so they must be doing a good job.
I usually wear a belt buckle that has an image of a gun, knife and brass knucles (http://farm4.static.flickr.com/3029/2548712528_235f7d1a99_o.jpg).
It's about 3 sq. inches and almost always skates right through with my bag. But, a few months back it got my bag scanned 4 times, and inspected twice at one gate checkpoint at AMS. On the same trip, I had a MSP TSO that acted like he found the holy grail when he pulled it out of my carry-on. Idiots.
This actually happened to me a month or so after 9/11. I had an autographed (by Charlton Heston, no less, RIP) .45 caliber bullet keychain, which in essence was a piece of brass covered with chrome plate. Well, you guessed it, the screener wouldn't let me through (I made the mistake of putting it in the bowl next to the metal detector) Anyhow, I tried, in vain, to save my precious keychain, offering to mail it back to myself, check it, anything. She had none of it. Undeterred, I demanded to speak to the local police, who agreed it was harmless. No such luck. I then had a National Guardsmen (armed, but with no ammo) confirm it was harmless. No dice. When I pleaded with her that it was Charlton Heston who signed it, I was met with "I don't know who that is." All told, I spent fifteen minutes wasting security's crime, when who knows what could have gotten through. Finally, I just yelled at security "Which one of y'all knows who Charlton Heston is?" A kindly older TSA agent stepped forward, and I gave it to him on the condition he'd put it on HIS keychain for work. With a twinkle in his eye, and a wry smile, he did just that, in front of all involved. God help us all.
@Jean-Claude: if he had no ammo, he wasnt armed. He was simply an umbrella-stand to provide terrorists with modern firearms.
Not long after 9/11 I was flying for work, and I dropped my keychain in the "bucket" before passing through the metal detector. When I get to the other side, the TSA guard is holding my keychain and inspecting it closely. I had forgetten that on my keychain was a key-sized, flat head screw driver that I'd had throughout my years in the Army. It was worth less than 10 cents I'd guess.
I got pulled aside and asked about it, citing that screw drivers were forbidden, and I was offered a chance to fill out a bunch of paperwork and have it mailed to my home. I declined explaining that the time spent doing that was worth more then the item, took it off my keychain and gave it to the TSA guard and moved on to my gate.
When I got to the gate, I realized that during that whole encounter I had a small pocket knife in my back pocket that hadn't triggered the metal detector.
So not only did they take away an item that I'd wager couldn't possibly have been used to accomplish any harm, they missed one that arguably could've.
I had a handheld amateur radio confiscated from my carry-on luggage in '95 on a flight from Europe back to the US (the radio was returning from its THIRD trip with me to Europe without ever having shown any intention of breaking loose and hijacking anything). They made it ride in a baggie in the cockpit, then gave it back to me in Atlanta for the connecting flight to my home airport. I guess its ok to use a radio to blow up a plane over the US, but not at sea - that would violate ICAO rules.
They should not allow SouthPark to set government policy. Wait - on second thought, it might actually be an improvement.
@ Unix Ronin (and probably others),
have you actually read my comment? I mean really read and understood it?
I haven't said that it is right to ban t-shirts (or anything else for that matter) because it is offensive.
I've just pointed the difference between stopping him wearing it for security reason and because someone thinks it might be offensive. That's two different things, quite different things actually.
I'm not judging if banning offensive t-shirts or other items might be right or even achievable. It's not what the original blog posting or even this blog are about.
The proper action is to do whatever it takes to keep the shirt then once the plane is airborn, restore it to its proper wearing position. Fuck the irrationals. And the primes.
@bob: I'd beg to differ. As it is, I'd be more afraid of a Marine with a pencil than a terrorist with a knife and pepper spray. God bless those who cut their teeth on concertina and piss napalm.
This seems like our "zero tolerance" school policies are moving into airport security.
Some school administrators have taken these policies to strict extremes...4th graders being expelled / send for psych treatment for playing cops and robbers and making a gun shape with their hands, stick figure drawings with stick figure guns, and so on.
I've detested this in our schools, but now, this insane "sympathetic magic" security is becoming part of airport security...words fail me.
At least for the moment, it seems a rare event. Of course, it might be changing as more of the generation that's grown up with the zero tolerance school system reaches job age.
I had a small (golf-ball sized) piece of quartz confiscated because it was "a projectile". I protested that it wasn't a projectile, it was just sitting there, motionless.
After all that fuss, I had to buy a large glass bottle full of flamable alcohol in the duty-free to make me feel better.
Armin: your comment was read, and you're simply re-iterating much of what Bruce originally wrote. The problem is that security are being used to filter for both actual security, and clothing taste. Security should be dealing with security. They should not be wondering whether a belt-buckle, or a t-shirt or a button-badge "could" be deemed "offensive". If they're doing that they're paying less attention to the actual security, which is what they're supposed to be there for, and what they're supposed to be doing.
As Bruce said, "every false threat the screeners watch out for make it more likely that real threats slip through". If security are banning "offensive" t-shirts, that is a "threat" in this context. It may not directly be a security threat, but it is an additional thing security are looking for when screening passengers. This reduces the overal security of the system.
but .uk does have a written bill of rights, it's just that a lot of people ignore it because they find the references to "popery" unpalatable.
I've been through Heathrow's Terminal 5 last Sunday (BA to Germany too albeit not Dusseldorf) wearing a T-shirt showing a character wielding guns in some rather aggressive fashion. Security officiers didn't care at all. Picture of the T-shirt: http://openbsd.org/images/tshirt-13.jpg
I have also always wondered how they knew the water bottle I usually carry in my bag is empty.
Security check at big metal bird hut strange. Me see many people made throw match and lighter into trash, but him allow me on big metal bird with burning torch in hand. Him say nothing in book about bring something already burning. Them is so stupid.
@ John David Galt and jdbertron
I don't think that Bruce was referring to the Maths side of it but John's page really did explain quite well why false positives matter.
In short, the more false positives the system produces the less correlation there is between a positive result and an actual terrorist. If you get enough false positives then the TSA screening becomes no better than tossing a coin.
Proof that focussing on kids with t-shirts is going to increase the false positive rate: the correlation between real terrorists and kids with t-shirts is already lower than the existing methods for finding terrorists. i.e Real terrorists don't usually wear Transformers t-shirts.
Even worse than that, if real terrorists KNOW that wearing a t-shirt with a picture of a gun on it will bring extra attention then they will avoid wearing these sorts of t-shirts. This will bring the true positive rate down.
And all that is added on top of the fact that the human mind is finite and fallible so with more attention being paid to false positives (kids with t-shirts) the false negative rate will have to go up.
So this brain-dead idea will bring the false positive rate up, the false negative rate up and the true positive rate down.
My wife and I were going through a TSA checkpoint, and had just sent her laptop bag through the x-ray machine with a text book inside. The laptop itself went through separately. As soon as the laptop bag went through the x-ray machine, the TSA employee viewing the x-ray picked up the bag, noticed how heavy it was because of the textbook, asked if the computer was still in the bag and said she wanted it to go through the machine again.
If she was paying attention to the monitor, she should have been able to tell us if there was a laptop inside.
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