Originally Posted by JS
I would go along with that. The purpose is to deter hijackings by doing more than just a cursory glance but without the very expensive/time consuming searches (as in, physical searches).
That's why it's called "screening" not "searching". There really is a difference between an X-ray and a hand search, and likewise a walk-through metal detector versus a pat-down/groping.
I've never bothered to read the signs at the security screening lines: do they say that by going past a certain you are consenting to be "screened" or "screened" and "searched"? Or is the reference to "search" avoided by saying your bag may be "inspected" and you may be "patted down" - euphemisims for "search".