Here is an image for your imagination.
At the health club, finishing up a workout, I walk into the locker room. A fat, older, naked man is standing with his back to me and leaning on an open locker while talking on his cell phone. As I walk up, I hear him say, "and give me a couple of egg rolls with that...."
Now I understand the real reason why there is a rule against using cell phones in the locker room.