Sorry to hear it. Do you know what he got banned for? The Bungie BANHAMMER is usually permanent; however, the are also lesser punishments called [i]Restrictions[/i]. Restrictions are usually temporary; however, I'm not sure about the duration. The Bans are usually for violating the ToS or Code of Conduct... Some people have been reporting bans for picking up restricted/unreleased items (like the Legendary Ghost Shells) after exploiting a glitch into the locked/unfinished areas such as King's Watch or Jovian Complex. Griefing other players in action or words can result in a restriction (like a Chat, PvP, or Matchmaking Restriction)... Severe cases could be dealt with a ban. Bans usually affect the Console, not just the GamerTag. In accordance with the Ban/Restriction policy posted Bungie does not respond to reinstatement requests. If you know what happened, please share it with the community so it may serve as a warning to others.