TSA pretends that their screening catches weapons and bombs. We know from controlled experiments that they don’t catch bombs reliably. We also know from testimonials of friends that they let things like knives and live ammunition through their scanners because their staff can’t identify what they see correctly.
But it’s the TSA themselves that now supply proof that their efforts are arbitrary and likely unnecessary. They demand $75 for inclusion in a less intrusive checkpoint lane (“trusted traveler”), but also have a few random other travelers go through the same lane. While the less intrusive screening is appreciated, the practice of having random passengers screened the same way as “carefully pre-checked” passengers suggests that they aren’t too concerned about the difference between the two methods. One includes radiation treatment in pornoscanners, the other one doesn’t. It does appear that TSA is trying to get $75 per traveler plus a whole lot of additional personal information in exchange for not getting exposed to pointless attention of incompetent but intrusive blue-gloved checkers.