Thanks to the TSA holding the power, at the very least in the "Well if you have a dispute with my ruling just step to the side and I'll get my manager, hope they wander over before your flight leaves..." way, I have in fact had TSA agents take away my stick deodorant before.
I had never really thought of that, but the ability to make you miss a flight is an amazingly strong coercive power relative to the stakes.
The x-ray scanners usually have bold signs on them instructing you how to opt out. But if you do, they act as slowly as possible to ensure you never do it again.
