It happened to me yesterday in my college class. A classmate was conducting a lecture on sign language and asked for some volunteers. She had 4 signs for us to do and she assigned me the letter B. Since my grandmother had taught me sign language, I already knew it and proudly outstretched my hand...a little too proudly. It appeared I was giving something close to a nazi salute...needless to say, she had fun with me and the class after that. They all checked to see if I had Doc Martens on.