Completely agreed.

Well, high probability, no. Over 50%? No. But possible, and something that should be thought about a bit? Absolutely. We are spending a huge amount of money and resources thinking that Joe Schmoe has a bomb in his pants. Is THAT possible? Yes, probable? no. I'm just pointing out that we should not create additional huge holes in security while worrying about even more remote threats.

The 9/11 student pilots were pretty obvious by today's standards and poor students, but were still largely ignored. Pilot background checks will be a bit more thorough nowadays, and people will be more likely to report "suspicious" pilots, but there are far too many trainees and junior pilots for this sort of thing to be perfectly reliable. Having a sympathetic pilot or two somewhere in America would be quite valuable to a terrorist organization.

Yeah, what a horrific incident. I remember once listening to the audio of it, but I won't again. Awful. I think all of those guys (including the offender) are still alive -- he is in a prison somewhere forever.