1. People who swing one or more arms wildly when walking down a crowded city street. Not a day goes by in which I am not smacked, or near-smacked, by some idiot (usually a moron wearing headphones, oblivious to anyone or anything else around them. That's for another day though) flailing their arm as they walk, This is not necessary, jerks. The human body is quite capable of moving forward and staying balanced with a gentle back and forth motion of the arm. Cripes, at the very least, pay attention to things around you