I was just thinking about the face to face interviews they conduct. And it's true that there are atypical types who probably are and will be jihadis. El Al does pretty darn good. That's what gave me chills when I saw United 93 .. the looks, the eyes of the terrorists just stood out like a sore thumb, like the dead eyes of Atta. If they'd been interviewed, who knows what some savvy security type would've been alerted to.
Mooselimbs bent on mischief seem to come up with obviously cockamamie stories an incredible percentage of the time.