Most of it is completely unneeded, to be honest. The chances of another 9/11 happening are basically zero because of two factors: 1) better cockpit security, a

Most of it is completely unneeded, to be honest. The chances of another 9/11 happening are basically zero because of two factors: 1) better cockpit security, and 2) 9/11 happening. Before 9/11, a hijacking meant you were going to be late for dinner. If everyone cooperated, it would basically just be an inconvenience. Since 9/11, a hijacking means you are going to die. Turns out near-certain death is quite a good motivator for getting people to fight hijackers. Similarly, before 9/11 cockpit access was pretty lax. You weren't supposed to have other people in the cockpit, but it happened all the time. The door was there more to stop people from wandering in than keeping anyone out. Since 9/11 that door stays shut with very few exceptions - and it is now strong enough that breaking through the door is practically impossible. A pilot is never willingly going to open that door to a hijacker - see the "near-certain death" above. This would still apply even without any passenger screening at the airport. You can't really do anything once you get on board the airplane, so why even bother bringing anything on board?