I've banned from Xbox Live because I joined a 15th Prestige Lobby on Call of Duty: Black Ops and didn't know that he was doing that. When I joined his lobby, the background was all gray. So I backed out of the lobby as quick as I can. Then I blocked communications with the guy so he woudldn't send me another invite. Straight after that I filed a complaint for tampering. Then just continued playing Call of Duty: Black Ops. Then the next morning I turned on my Xbox and I got a message saying I was banned from Xbox Live.