Apple announced a while ago that they were going to shut down their MobileMe platform this year.
Users are being advised to switch to Apple iCloud. This meant that a lot of data shared by MobileMe users would have disappeared from the internet.
Archive Team worked along with Archive.org to backup whatever public data that they could before the service was permanently terminated.
Archive Team has finished downloading MobileMe and .Mac before Apple deletes it on June 30. 272 terabytes. 380,000 users. HUUAAARRGG!!!
— Archive Team (@archiveteam) June 26, 2012
And the group has just announced that they have recovered 272TB worth of data that should soon be available through archive.org platform.