Interesting followup on Jacob Sullum's post below, on the ExpressJet pilot who refused a full body scan. From an interview with RAND Corporation terrorism expert Brian Jenkins, in the November issue of Los Angeles magazine, alas not online:

In the wake of the Umar Farouk Abdulmutallab episode–the guy who had a bomb concealed in his underpants–even though the bomb didn't work, there was a great deal of alarm, and in response we decided to deploy full-body scanners. Hundreds of millions of dollars. One guy, one small device in his underpants, and we've just spent hundreds of millions of dollars.

Then, a page later in the story, so maybe you wouldn't notice the connection:

And, you know, I'm not entirely certain that a body scanner would have detected Abdulmutallab's bombs. Maybe it's not even likely? I don't want to get into technical details, but it's not certain…

Security theater: if only it provided entertainment commensurate with its expense.