On December 17, disgruntled players of the Xbox 360 exclusive, Halo 4, flocked to the official forum to "politely" inform Microsoft officials that they were receiving bans from the game after downloading the new Crimson Map pack from the Xbox LIVE Market Place.
The ban message recieved by affected players was ambiguous to say the least, failing to mention the reason for their ban but listed violations such as manipulating network conditions, impersonating Microsoft, 343i, or Bungie employees, and behaving in an unsportsman-like manner.
Since then it has been revealed that less than 200 players have been affected, and the issue since resolved... at least according to a statement Microsoft released today:
There was a situation yesterday (Sunday) in which less than 200 Halo 4 users were being incorrectly banned from accessing certain parts of the game (not banned from Xbox LIVE as a whole), and we have since resolved the issue. All players accounts impacted are working as normal. For more information, please go to the Halo Waypoint forums here.