One key point: the threats to airline security have come from abroad, and the U.S. should be focusing on flights coming from foreign countries. I had been thinking along the same lines. If nothing else, if domestic-based terrorists did want to blow up some planes, but airport security was too intense, what would stop them from bringing the bombs onto commuter trains in, say, Boston, New York, D.C., Chicago, and San Francisco? Or do we need to start patting down the genitals of all train passengers as well? And then what to we do about school assemblies, movie theaters, crowded shopping malls, sporting events, and so on?