Seriously, though, Kevin says the following, which makes a lot of sense:
According to security expert Bruce Schneier, "[e]xactly two things have made airplane travel safer since 9/11: reinforcing the cockpit door, and convincing passengers they need to fight back. Everything else has been a waste of money." After all, the 9/11 strategy stopped working on 9/11, as soon as passengers learned what was going on. (Ask the shoe and underwear bombers where all those bruises came from.) And yet we are still so terrified of a strategy that worked for less than one day that, ten years later, we scramble fighters in response to a slap-fight or long toilet stay.
Read the Schneier link, too. I think he's right.