> The first is: The TSA probably doesn't need to exist at all in its current form; I'm not aware of any evidence they actually do anything to stop actual threats.

In my anecdotal experience. Literally hours before Air Canada plane crash on American airport I was flying from a Canadian airport. The agents after telling me to enter full body scanner with my hands up prevented an inexcusable violation - me bringing on board 0.33l unopened sealed bottle of still water, which funnily I got on board of a plane on previous flight. You got the risk management all wrong, all over, everywhere.

Still, Canadian airport security is probably nicer than TSA.