I have had an Xbox Live account for 6 years and last year while playing Halo 4, I unexpectedly was kicked from a game and was left a message telling me that only accounts with a valid gold membership could play matchmaking. I was absolutely shocked and thought I'd have to forget my account forever... Turns out Halo has a rubbish banhammer which they don't tell you about... The lesson is to not quit games while playing Halo 4 matchmaking! Fortunately I haven't had a console ban but it would make me sell my Xbox and never play again.