Argument: Scanners do not reveal things in body cavities
Rep. Jason Chaffetz, R-Utah said on January 9th, 2010, according to the Chicago Tribune: "It is a whole body image, and they can spin it 360 degrees. And they can zoom in and see something as small as a nickel or dime. But they can't spot something hidden in a body cavity. A good, old-fashioned sniffing dog is more effective."
Steve Chapman. "The Naked Truth about Airport Scanners." Reason. January 7, 2010: "The more intractable problem is that terrorists are fiendishly capable of adaptation. If the scanners can find plastic explosives hidden in underwear—which is not guaranteed—the evildoers have another option that would foil these gadgets: hiding the bomb in a body cavity.
That’s exactly how one suicide bomber tried to assassinate the prince in charge of counterterrorism for Saudi Arabia. The charge went off, and the prince was lucky to survive. Today, full-body scanners. Tomorrow, cavity searches?"