This didn't happen to me but to my brother in law.

He was on an elevator at hotel in las vegas and onto the elevator walks fucking Marilyn Manson and his bodyguard. My brother in law at the time KNEW I loved Manson, and he leans over to him and asks hi very politely. "Mr. Manson, my brother in law loves your music, would you please sign an autograph?" Manson ignores him. So my brother in law, being the intelligent person he is goes to tap Manson on the shoulder and the bodyguard grabs my brother in laws hand and twists it. However, my brother in law was a wrestler, so he's able to reverse he situation and put the guard in a headlock while manson is cowering in the corner. He winds up forcing manson to sign the autograph and then rips it up in front of him before walking out. yep.