Residents of the German state of Hamburg do not have to register under their own name on Facebook. The profile site should not block accounts with pseudonyms, and they are not allowed to be changed by hand. This is a new rule which has been made by the Germans.
The Germans in the city of Hamburg can use pseudonyms on Facebook and Facebook is not allowed to force the users to provide their “real” information.
It is not yet clear whether the decision has implications for Facebook users outside Hamburg.