Technically TSA can search you anytime they want in the sterile area. All the more reason to talk to you congress person to get them gone.
I recently have been seeing a ton of TSOs just walking individually around various airports. sometimes they are talking to airline staff, other times they are watching the TVs that some airports have throughout. I wish there was an easy way to tell if they are on break b/c it really just gives the impression of thousands standing around.