Some users are banned permanently by the Microsoft. These banned users were claimed to have illegal access to downloadable content. Official forum of the Xbox is where this statement was posted.
According to Microsoft, in their recent investigation they have found users accessed Xbox Marketplace Live into the downloadable content illegally. According to their investigation, the access was very much intentional and not by mistake which is a clear violation of the terms assigned by that service. Microsoft didn’t reveal any information about the individuals regarding this in their announcement.
They also said that they are very careful and they have clear proof of the account and issued them eternal suspension from all the services. They apologize for not revealing the personal information about the users and thanked all for the cooperation regarding this subject.
In the end of their announcement Microsoft said Cheers! which makes that bans look friendlier. Eurogamer in their report saying some of the banned Live users dispute the accusation. Also according to the Eurogamer report the bans are not for lifetime. It will expire on 12/31/9999. They will have to keep themselves alive till then!