This is a bit old, but I just ran across this (yes, through yesterday's
Slashdot article).

This paper by MIT students statistically proves that the CAPS system
(computer assisted passenger screening) that the TSA advocates is inherently
vulnerable to dilligent terrorist tactics, and could make the whole system
less secure.

http://www.swiss.ai.mit.edu/6805/stu...apers/caps.htm

Publishing this does not make anyone less safe. The 9/11 terrorists knew
this algorithm intuitively and made a few "dry runs". And I suppose
security screening is irrelevant to the 9/11 situation anyway because they
weren't carrying anything illegal. Pocketknives and box cutters were legit
before that day. But any repeat attempts would surely use the tactics
outlined in the paper to increase their odds of success, and from the looks
of it, CAPS will only make things worse.

So, the only people that get screwed out of this are law abiding citizens -
once through the extra trouble and privacy intrusion at checkpoints and
twice through the diminished effectiveness of overall security.

Wonderful... :-/

-Aviv