This article gives some insight into the flaws of the National No-Fly List associated with CAPPS and CAPPS II. Along with the horror stories of existing problems, there are examples of why the new plan for CAPPS II is even worse than the current one.
"Remember, this isn't just about privacy, it's also about accountability," Tien says. "It's not just Orwell -- it's Kafka."
A bigger problem with CAPPS II, though, is that it may not work very well at finding terrorists. In May 2002, Samidh Chakrabarti and Aaron Strauss, two graduate students in computer science (and a few other disciplines) at MIT, decided to see if they could come up with an algorithm that terrorists might use to beat a profiling system like the current version of CAPPS. After studying everything that is publicly known about CAPPS, the pair determined that anyone with the will and not very many resources could easily get around the system. They concluded that airlines would be safer if, instead of profiling, they instead selected a portion of fliers at random and subjected them to more thorough searches for weapons. (Chakrabarti and Strauss wrote up their findings in a term paper for a class, but it was picked up by First Monday, a peer-reviewed academic journal on the Web.)
'Please step to the side, sir'