Um, this is like the ONLY thing that the TSA has done that I actually agree with and can make a difference... assuming the agents are properly trained. Thats the big IF.

Its called behavioral profiling and is the most effective way to catch someone who has intent do something. A trained people can spot certain actions that are common among someone trying to hide something. I'd much much much rather answer a couple questions than go through the useless nude-o-scope xray scanners.