I found this piece by TNR's legal commentator Jeffrey Rosen on those full-body scanners at airports striking and persuasive. His contention is that the millimeter scanners "are a virtual strip search -- and an outrage." They give somebody somewhere in a booth an anatomically correct view of the passenger, but they would not have detected the explosives the panty-bomber carried. Earlier in the development of the machines models that at least blurred facial features, but those have not been adopted. Maximum invasion of privacy almost seems to be the goal.
The upshot is that in response to the Christmas would-be bomber, we have imposed yet another degrading invasion of privacy on ordinary airline passengers, and one that doesn't really increase safety or security. It's like a knee-jerk response. Screw up -- this was a government screw-up caused largely by the fact that we have too much security bureaucracy, too many different agencies looking at various pieces of the terrorism puzzle but so caught up in bureaucratic procedures, turf issues and empire-building that they don't -- perhaps can't -- communicate with one another. A would-be terrorist fails on a difficult, long-shot bombing attempt and the government responds by terrorizing ordinary innocent passengers. Truly the terrorists have won.