Originally Posted by ttjoseph

I think you may be missing the original point here. If someone can walk away from a search at a TSA checkpoint, a malicious group can simply keep testing the checkpoint using different methods of concealment until one works. In this way they can, without penalty, learn how to bring some dangerous item on a plane (such as a gun or 4 ounce bottle of shampoo), and then actually do it.

If you assume the TSA's approach to security is fundamentally reasonable (ha ha) then this line of reasoning does have merit.