Jo Yardley had an article up a day or two ago about the fight between Facebook and Germany. It seems Germany has some law that prevents Facebook from requiring identification as it violates German privacy laws.
Germany fights Facebook thus perhaps paving the way for using pseudonyms

Mezzaluna
Today we hear Facebook has decided to allow German users to use anonymous names/pseudonyms . But, only Germans and ONLY residents of Hamburg. It is no surprise to me Facebook complied but only allow pseudonyms in this very limited area.
German privacy laws put Facebook in a bind. They either complied or kicked out their Hamburg Germany users. There are 80± million Germans and something less than 2 million live in Hamburg, so while that is a lot of advertizing eyes it isn’t much of Facebook’s user base.
See: Germans allowed to use Fake Names on Facebook, while everyone else CANNOT.
Expect Facebook to come up with some way to limit new signups from Germany that cannot provide RL ID. While Facebook can’t kick someone out for using a pseudonym there is nothing that says they have to let someone in that uses a pseudonym. So, expect a change in Facebook’s signup process.