Stop the panic on air security - CNN.com:
We're going to beef up airport security, because Umar Farouk AbdulMutallab allegedly snuck a bomb through a security checkpoint. We're going to intensively screen Nigerians, because he is Nigerian. We're going to field full body scanners, because they might have noticed the PETN that authorities say was hidden in his underwear. And so on.
We're doing these things even though security worked. The security checkpoints, even at their pre-9/11 levels, forced whoever made the bomb to construct a much worse bomb than he would have otherwise. Instead of using a timer or a plunger or another reliable detonation mechanism, as would any commercial user of PETN, he had to resort to an ad hoc homebrew -- and a much more inefficient one, involving a syringe, and 20 minutes in the lavatory, and we don't know exactly what else -- that didn't explode.