Here's another interesting bit: yep, many potential bad-guys have legit passports and thus wouldn't be stopped or ever deterred by the requirement... and after listening to a counter-terrorism expert speak on his study of over 400 terrorists (including the 19 9/11 hijackers), most don't have criminal records, either, and almost all can get legit IDs w/o a problem and can use their real names as well.

We'd be better served finding them at the group-forming phase on the Internet, where they first meet up and begin to form the group mentality that will permit otherwise sane and stable people to do things like 9/11.