I was at an airport this weekend, and before you board, you have to go security. And that means you have to go through a metal detector. Well, when I was going through security, the airport security workers were transporting wheelchairs somewhere, and every time a person went through the metal detector, the thing went off because the other people were moving the metal wheelchairs. So they had to send the person back through the line, wait for the wheelchair people to stop moving, and then make the person walk through the metal detector again.
And the best part was, the guy always thought we were hiding something metal. He never thought, "Hmm, maybe we should stop sending those metal wheelchairs through at the same time as the passengers." Nope, he was thinking, "The thing went off! He's got a weapon! ARREST THA--well, let's make him go through one more time just in case. ... Drat."