by intelligent profiling, I mean more the way the Israelis do it: psychological profiling, looking for telltale signs of nervousness/guilt etc., ranking people by profession/origin/appearance, and randomly singling people out for more extensive scrutiny (but not so random as to nab the 80-year-old grandmother in a wheelchair).

Israeli airport profiling also uses religious and ethnic or national origin. When I've heard people endorse it as a good model for the U.S. in the past, I thought they were often saying they wished U.S. airport screening would use those things.

> ranking people by profession/origin/appearance

So a white computer programmer from Seattle might be "safer" than a brown janitor from Dearborn?

And right there is your discrimination lawsuit. No government agency wants to expose themselves to that kind of challenge, even if they might win.

But that kind of profiling involves human judgement in a qualitative way, which is not very popular in the US.

Instead, we prefer to use metrics, which we can mesure, aggregate and compile in neat reports. But metrics are a projection of a multidimensional situation onto a few dimensions, and hoping we picked the correct projection.

I'm all for collecting stats but I wish that was just a tool used in addition to a broader qualitative approach.