I think you're confounding "TSA" with specific methods introduced with the TSA like body scanning and enhanced pat downs that are of dubious value.
No, I am specifically talking about those methods. You have yet to establish that there is anything to deter. You've just declared that the TSA protects us (while stealing shit).
It's an easily supportable assertion, unless you insist that I prove a negative assertion *by example*, which is of course impossible to do.
Well, we can look at the number of hijackings/attacks in the decade leading up to 9/11 (on us flights) and in the decade after. I count 1 attempt before (someone hijacked a cargo jet in 1994 so they could fly it into fedex HQ) and 2 or 3 attempts (shoe guy and underwear guy) with zero effectiveness from the TSA for the after, so we do see some attempts being made, but the TSA did nothing to detect/preent them. With that level of egg on their face, you would expect them to crow loudly about anything they actually did right, but instead, they're trying to harass train travelers. basically, they don't do shit, so why do we have them?