[Bruce Schneier]: The ID checks. There have been exactly two things that have improved airport security since 9/11: reinforcing the cockpit door and teaching passengers that they have to fight back. This whole ID check everywhere is ridiculous. Everybody has an ID. So what? Osama bin Laden has an ID. All the 9/11 hijackers had IDs. You can fly under a fake name and a fake ID really easily. It's pure security theater.
(http://www.sevendaysvt.com/features/2006/tales-from-the-cryptographer.html)