Like I said, they are attempting to stand on a carved out area of extra-constitutionality. (Which, yes, could then be extended to trains, subways, buildings, other search tactics, whatever). If as Katlee noted all government employees are required to take an oath to uphold the Constitution, there is a little problem there.
That's all because "probable cause" doesn't exist. Oh, and after you send them to prison and then they get out and register as sexual offenders, they can go back to working for the TSA if ten years goes by and they are not caught again.
http://www.internationalskeptics.com/forums/showthread.php?t=192711&page=10
The problem is you don't understand what the Constitution actually says.