Via Bruce Schneier, a really good article about security theater:
At the time, it seemed reasonable. Richard Reid tried to ignite explosives hidden in his shoe while aboard a December 2001 flight from Paris, so Congress banned butane lighters on planes.
But in retrospect, the costs of the ban outweighed the benefits. Airport retailers had to stop selling lighters. Lighter vendor Zippo Manufacturing Co. laid off more than 100 workers in part because of the prohibition. Transportation Security Administration screeners at one point had to confiscate 30,000 lighters every day, quadrupling the amount of garbage the agency had to dispose of. TSA even had to hire a contractor to help with all the extra trash.
Welcome to homeland security, where everyone has an incentive to exaggerate threats. A Congress member whose district includes a port has little to lose and much to gain by playing up the potential for container-borne terrorism. A city with a dam talks up the need to protect critical infrastructure. A company selling weapons-detection technology stresses the vulnerability of commercial aviation. A civil servant evaluating homeland security grant applications has an interest in over-estimating dangers that might be addressed by grantees rather than denying funding and risk blame in the event of a disaster.