In Houston (ICA), I went through the security station. The first agent said to the guy in front of him, "You might want to take off your shoes." The guy asked whether he had to, and the agent said it was up to him. He took off his shoes.
The truth is, they are going to check either way. It is your choice if they do it there thru the machine or with a secondary check. For some reason, AFAIK, the actual TSA screeners are not allowed to indicate this to you, hence your badly worded answer.
Someone want to explain to me how the decision to pull me from the line on that basis makes us safer in the air?
Sure....
Racial profiling has been a major debate in the United States for decades. Immediately after September 11th, national polls showed that the majority of Americans supported profiling in airports, with the idea that it would help catch more terrorists. Civil libertarians and privacy advocates argued then and continue to argue that profiling is discriminatory, unconstitutional and ineffective. Profiling advocates claim that profiling makes sense because you can focus your attention on those people most likely to be a threat. Independently of these debates, all major U.S. airports use a profiling system called CAPPS (Computer Assisted Passenger Pre-Screening System) to try to catch terrorists and people trying to do harm.
But now, two MIT Computer Science graduate students say they have proof that profiling doesn't work. Samidh Chakrabarti, 23, and Aaron Strauss, 22, say that using purely random searches would be more effective at catching terrorists.
CAPPS was put into place in 1999. The system profiles passengers and identifies those who should get extra security screening. While the parameters of the system are classified, anyone who is flagged for extra screening knows it as soon as they are pulled aside for special treatment. Chakrabarti and Strauss show, through computer modeling, how the terrorists can easily defeat the system. Put simply, it's all about trial and error. For example, let's say a terrorist cell sends 20 different guys through the airport (with no weapons and no intent to harm), the person who consistently passes through security without extra scrutiny is the best person to send on a destructive mission in the air. The terrorists basically conclude this guy is "profile proof."
On the other hand, according to the MIT grad students,
if the airports employed only random searches the terrorists would not be able to practice against the system. The MIT research explains it this way: an average airport has the ability to do extra screening on eight percent of the passengers. Currently, the CAPPS system uses profile criteria to choose up to six percent of those people for extra screening, the remaining two percent are selected randomly. But if all eight percent were selected randomly, the MIT research shows there is a better chance of catching terrorists or people hiding weapons. That's because with a purely random system, potential terrorists would have no way of knowing ahead of time if they were likely to receive extra screening and they would have no way of practicing against the system.
Chakrabarti and Strauss came up with the idea for this research while they were taking a class together, jointly offered by Harvard and MIT, called "Ethics and Law on the Electronic Frontier." They decided to look into profiling and airport security since they were hearing so much about it in post 9/11 news reports. They say they didn't set out to defeat the CAPPS system, they just started looking into it. Then one day, in a brainstorming session, it just occurred to them that because the system gives you feedback about your CAPPS status, terrorists would be able to use that information to practice against, and eventually, subvert the system.
Doug Laird is a private security consultant and the former Director of Security at Northwest Airlines, who helped craft the CAPPS system. He says that while the paper is compelling, he doesn't want to make the public unnecessarily worried at this point. Laird says Chakrabarti and Strauss make some incorrect assumptions about how the CAPPS system works. He cannot identify which assumptions are incorrect because that information is classified. Independently of those assumptions, ACFnewsource asked Laird about the fundamental argument of the paper, that any profiling system that gives you feedback on whether or not you fit the profile, no matter how good that profile is, is in danger of being probed and exploited by potential terrorists. He didn't have an immediate answer. Laird says he doesn't necessarily argue with that assertion. His main concern is whether the number of probes required by potential terrorists would be prohibitively expensive in both time and money. Chakrabarti and Strauss argue that potential terrorists could get enough information about their CAPPS score in as few as six plane rides or three round-trip tickets. Laird says he believes that number to be incorrect and is working with an independent statistician to evaluate the conclusions in the paper.
ACFnewsource contacted its own independent statistician. Dr. Philip Stark is a Professor of Statistics at UC Berkeley, the top ranked statistics department in the country. Stark reviewed the paper. He had some initial questions about some of the probability equations, but he says even if the equations are slightly off, it would not be by enough to change the conclusions of the paper. He says the model the MIT grad students used is actually very similar to a common aspect of mathematical game theory. The "game" he cites is called "matching pennies."
It works like this: you and I each get a penny and we each decide to put them down as heads or tails. If they match, you keep both, if they don't match, I keep both. Then the question is: what is the best strategy to win the most pennies? All heads? All tails? Two heads then two tails? The problem is that if there is any sort of pattern, your opponent can detect it and counteract it.
It turns out the best strategy is purely random (flip the coin). Stark says this is a well-established concept in the mathematical world, that as long as there is a detectable pattern, then it can be exploited. This is, Stark says, the same concept behind the MIT paper. As long as there is a pattern, your opponent can figure it out and work against your pattern, in the case of airport security, the pattern is whether or not your CAPPS score is high enough for you to be pulled aside for extra security searches. But, as with the pennies, if the pattern is purely random, you cannot know what will happen ahead of time.
The MIT paper is making its way around the computer science and security communities. Bruce Schneier is a computer science and security expert as well as the CTO of Counterpane Internet Security in Cupertino, California. Schneier also puts together a monthly newsletter called Crypto-Gram. Schneier circulated the MIT paper on his newsletter before it was even published in First Monday, when it was just available on the MIT Web site. Schneier says he thinks the research is well done and the students came across an interesting idea, but he sees two problems. First, he says in order for the model to work, terrorist cells would need a sufficiently diverse population to choose from to find operatives with low enough CAPPS scores. Schneier questions the likelihood of that. Second, he, like Laird, questions whether the CAPPS system is more complex than Chakrabarti and Strauss assume, and whether that means that the number of probes required of the terrorists to be assured of their CAPPS score would be prohibitively expensive.
But Chakrabarti and Strauss answer both these concerns in their paper. In terms of terrorist diversity, they point to John Walker-Lindh, Richard Reid and Timothy McVeigh. All of whom do not fit the typical terrorist profile, but who have taken part in terrorism. In terms of the number of probes being prohibitively expensive in both time and money, the authors point to all the time and money spent by the 9/11 terrorists. Many of them spent years in the United States, attending flight schools, and taking commercial flights repeatedly to make sure they understood the security they were up against.
Chakrabarti and Strauss recommend that if profiling stays in place, airports should find a way not to give feedback about who has a high CAPPS score. Additionally, they recommend that instead of spending more money to improve profiling, security efforts should be focused on the administrative level so that everyone is going through extra screening.
As this research continues to make its way around the scientific community, the Transportation Security Administration (TSA) has yet to make a public comment about the paper. When contacted by ACFnewsource, Heather Rosenker, a spokeswoman for the TSA said she was familiar with the paper, but that the TSA wouldn't make any comment since they are in the process of "upgrading to a new system." Chakrabarti and Strauss have made no attempt at contacting the TSA. But they say one civil libertarian who read the paper, told them he gave it to the TSA. The authors also say they have heard through back channels (that they cannot reveal) that the TSA is circulating the paper within the organization. But one thing seems clear: if the architect of the CAPPS system, Doug Laird, cannot dismiss these findings, perhaps some serious discussion will come out of this research. For his part, Laird says he is "on the fence." He thinks if Chakrabarti and Strauss really believe in these findings they should be doing everything they can to contact the TSA and try to get a grant to work with them to improve the system. For their part, Chakrabarti and Strauss say they are just academicians who have done their work and it is up to someone else to affect policy.