A few years ago I was on a school trip, and we were flying back to the US from London. The security at the airport asked me if I minded going through a new type of scanner with a shorter line. The airport was doing a test run of the same kind of backscatter machine. Everyone likes short lines, so I agreed. After the scan was over, the security showed me the scan of my backside. It was literally an inverted naked picture of my ass. They looked at the scan of the frontside, but didn't show it to me. I wasn't expecting anything like this, because the technology was so new and it hadn't been widely publicized. It was really embarrassing to think that I had just been practically strip searched.

That image is a fake, but it's not very far from the truth.