Every day when I commute to work, I ride the DC Metro. It holds as many people as an airplane does, if not more. Subways have been the targets of terrorist bombings in the past, and yet I don't so much as pass through a metal detector before boarding. And you know what? That's fine. Everyone accepts the miniscule risk, because it isn't worth the time, money, or liberty to set up TSA-style anal probes at every turnstyle for the Metro.
It is insane to be wasting so much money on this **** at our airports. People have absolutely lost their minds. The risk of being the victim of a terrorist attack is tiny.