Like I said in another thread, if they were selecting the "right" passenger then I don't think there will be a problem, but what's the guessing that they won't select based on known profiles, but it'll be yer 80 year old granny, or as Bugged said it'll be the aircrews who get put in the box every time. We already know that at some places aircrews are picked on and made to under go the full procedure EVERY time they pass through security, even if they don't beep they are "selected" for extra checks.