Schneier, Bruce. “Airline security a waste of cash.” Wired news, December 1, 2005.

Summary: The measures that the American government has taken to prevent terrorist attacks using public air transportation have failed to detect any terrorists, but they have prevented thousands of legitimate travelers from flying, some because they have the same name as a suspicious character, some because they were added to the government's database by mistake.

It is just not true that one can detect terrorists by comparing everyone to a fixed profile and picking out those who match. The programs that attempt this just give the participants an unwarranted sense of safety.

Exactly two things have made airline travel safer since 9/11: reinforcement of cockpit doors, and passengers who now know that they may have to fight back. Everything else -- Secure Flight and Trusted Traveler included -- is security theater. We would all be a lot safer if, instead, we implemented enhanced baggage security -- both ensuring that a passenger's bags don't fly unless he does, and explosives screening for all baggage -- as well as background checks and increased screening for airport employees.

Then we could take all the money we save and apply it to intelligence, investigation and emergency response. These are security measures that pay dividends regardless of what the terrorists are planning next, whether it's the movie plot threat of the moment, or something entirely different.