1. Or literally the TSA: http://www.nytimes.com/2013/08/06/us/tsa-expands-duties-beyo...
Our small satchel bags and bodies did not get x-rayed, but the large suitcases did. I forgot I had a pocketknife in there (as it's fine usually for airport security as a check in bag). Somehow, when my suitcase got scanned, they mixed up the order and the person behind me got stopped for having a knife. By that time, I was making a quick getaway to the platform as I didn't want to lose the knife.
I could have just had a knife (and bomb?) in my satchel bag, so was pretty confused by the whole x-ray suitcases only situation.
It's not exactly airport style - at least in NYC and Philly they swab you for explosives and check your ID. No X-Ray or nude-o-scope. You're free to not go through the checkpoint (but you won't board your train).