I know this may incite a flamewar, but I thought I'd share this.... strange observation for discussion.

The other day at BWI, early morning rush, I present my ID and my boarding pass to the private ID checker and wait in the maze of travelers to go through the metal detectors.

An average looking, middle-aged gentleman two places in front of me alarmed the WTMD. He was shoeless, and the screener said that the metal detector seemed to suggest he had a metal object on his left leg. He shrugged, and removed his wallet from his pocket, lots of loose change, keys, , etc.

He walked through again and once again the machine alarmed. For some reason, the TSA agent let him attempt a third time, this time informing him that once again, the machine had a hit on his left leg region.

He removed his belt and walked through a third time. BEEEP - Metal object, left leg! TSA agent gestured him towards the glassed in "penalty box" for secondary. The man then stated "Oh, that's right! I had surgery on my leg and it has some screws in there. That is probably what set it off, here, I can show you a card I got from my doctor."

At this point he reached for his pocket as if going for some kind of card, but the screener said "No, sir, that is ok, I trust you. You can go through." and gestured him through the WTMD.

It was a bit early, so it wasn't for a few minutes as I sat down at my gate eating a breakfast sandwich that my eyes bugged out and I realized the potential implications of what just happened.