PROFILING: It's controversial but done correctly it's effective, says this New York Post op-ed (registration required). Ask the Israelis:

Following a spate of terrorist hijackings and other attacks on civilian aircraft and airports in the late 1960s and '70s, Israel developed a security system that utilized sociological profiles of those seeking to harm Israelis, among other factors. The American system developed at the same time relied primarily on technology like scanning devices, which checked people and baggage uniformly. Facing a less benign threat, Israelis found this system insufficient: Explosives and other weapons could slip through too easily. Since it wasn't feasible to perform extensive security searches on every passenger, Israel used sociological profiles in addition to screening devices: Each passenger is questioned briefly and then airport security personnel use their judgment to identify suspect would-be passengers, who are then questioned at greater length and their bags searched more thoroughly. It is targeted and far more effective than random searches, which end up being nearly cosmetic. Screening and random searches would not have averted the tragedy that profiling stopped on April 17, 1986. Anne-Marie Murphy, a pregnant Irish woman, was traveling alone to Israel to meet her fiancé's parents. Her bags went through an X-ray machine without problems, and she and her passport appeared otherwise unremarkable.

The random-search method in the U.S. is ineffective, says writer Yishai Ha'etzni: "The American system's "blindness" cuts off the most important weapon in the war against terrorism: Human capability, judgment and perception. Now that the United States faces a higher threat, it cannot afford to neglect those tools."