John Mayer grew up in my hometown.

We learned guitar from the same person. After John Mayer started getting some publicity and local fame, our teacher proudly put up a John Mayer poster in his practice room/office. He was so proud of "Johnny," and talked about his progress while beaming at any opportunity. It was like his son had just graduated from Yale. Anyway, one day, John comes in, sees the poster, and, long story short, tells THE MAN WHO TAUGHT HIM GUITAR that he can't use his face for advertisement without his permission, and threatens legal action.