Yes, I don't think the 9/11 scenario could happen again, unless the hijackers gas all of the passengers or something. I'm sure they will fight back, as they have on numerous occasions after the attacks. But, where there's a will, there's a way. I also thought recently about the Egypt air thing. What if one of the pilots goes to the lav, and the other guy is suicidal? I know this is rare, but with these new doors, the other guy will have no way back inside the cockpit if the one in there want's to be alone. I don't know what to do about that one..