"`It can't just be technology,'' says Gerry Leone, the former U.S. prosecutor who handled the 2002 case in Boston against ``shoe bomber'' Richard Reid. ``There have to be observations made and people who are well-trained to know what combinations of things should lead to increased scrutiny.''

"Opponents including Muslim groups and the American Civil Liberties Union are wary of expanding government powers or opening the door to racial profiling, while airlines want to avoid significant delays and higher costs. Also, some El Al measures may not work on a larger scale. "