The National Research Council say data mining and behavior detection are not useful in detecting terrorists.

http://www.cnn.com/2008/US/10/07/ter...ior/index.html

And TSA agrees!

A TSA spokesman said Tuesday the report "is not any kind of indictment of our program," adding that the TSA's behavior-detection officers do not claim to be adept at finding people with terrorist intent.

Instead, spokesman Christopher White said, the officers look for people exhibiting signs of stress, fear or deception, and focus on those people for further investigation.