Last week came the news that Ubisoft would be taking down a DRM server, which would result in a few games no longer being playable. Those games require an always-on connection, and without the DRM server to give the green light, Tom Clancy's HAWX 2, The Settlers 7, and Might & Magic Heroes VI would be unplayable. Those were supposed to have been the only games affected, but now it looks like Anno 2070, Driver: San Francisco, and Assassin's Creed: Revelations are all unplayable. All three of those games were listed as "safe" during the server move, but that does not appear to be the case. Ubisoft has issued an apology of sorts, and is working on a fix.
Why more games are affected than originally announced is unknown, nor is the reason why the games are unplayable to begin with. If the server move would impact some games, one would hope a backup option is in place to let gamers play the games they bought. In the world of draconian DRM measures, Ubisoft's plan certainly has become even less popular due to this snafu. There is no word on when the server will be back online, either.