A girl I used to work with as crew used to LOVE security.
Every day she would pack her bag with half a dozen assorted sex toys, rush through the walk through scanner, then watch the faces of the screeners as her bag flashed up on screen.
Personally, I find that if I dress/pack appropriately, security is no hassel. Particularly if in uniform. Straight to the front of the line, bag goes straight through, no beeps if you have the right shoes/belt (can be hit and miss there), and bingo, a completely painless 30 second delay in getting to the aircraft.
I agree, its all a bit theatrical for my liking - especially when you walk past builders renovating an airside retail outlet, with their assorted 'saws', 'nail guns' and other fun dangerous toys laying about. If someone was very determined to do some damage, they could.
You are only supposedly protected if you fly on an airline/aircraft operating a service from a secured airport. I know that at least in this country, theres planes flying around with up to 99 pax on charter, with no screening.