Several years ago I was in a Conrail yard with a professional photographer to shoot photos of a new product we were working on. He set up a polaroid to take a preview shot, and handed it to me for review when it was ready. I told him we can't use the shot at all. He looked at me puzzled and I handed the photo back to him. He looked closer and then it hit him.
There was a graffiti covered car in the background that had references to Conrail, a derogatory sexual act, and a derogatory term for a certain minority group. Oops. We moved the tripod and set up again!