An article in the New York Post explains some of Israel's security procedures around public transportation. There is a main emphasis on the HUMAN element - trained security personnel taking in a traveler's look, demeanor, attitude, dress, then comparing these to how he or she answers simple questions. If something seems suspicious, further probing and interrogation comes. All of this in addition to metal and bomb detectors.
In the U.S., get past a metal detector and you're through...
There has been plenty of press mentioning our lack of human intellegence on the ground throughout the Middle East and the world. I think the lack of human intellegence in our country's defense here at home is rather suspect. Which would you think more imposing to a potential terrorist - a predictable array of machines manned by low-wage, equal-opportunity workers, or a group of well-trained interrogators backed by military police with large weapons?
But, guess which choice would make ACLU lawyers salivate to dehydration?