I don't think today's security [b]would[/b] prevent someone from commandeering an airliner and flying it into a building. He might not be able to get on board with a knife of any kind, but I don't think too many people would rush him even if he had no weapon...sad but true. I'm not so sure that I believe the USAF will be able to stop an airliner, either, unless it happens to be heading for a high-priority target - there are too many airliners in too much sky, and not enough fighters to cover all of them. All in all, I think today's security measures are more to give the American public the feeling that the gov't is doing something to protect them, than to actually provide that protection. Of course, confidence is an important thing, and the economy would be badly damaged if people weren't confident enough to fly for business, pleasure, etc. But what's the one [b]real[/b] thing that's come from the Homeland Defense office, after 9 months and millions or billions of dollars? A color-coded 5-step terror warning system! Smokey the Bear has been using the same kind of system to warn of forest fire dangers for decades now!