Germany (and the rest of continental Europe) has the droit d'auteur. You cannot transfer your copyright here e.g. if you join a company and hack away some time, you own the copyright to the code you wrote. You just don't own the license.
The philosophy of the GPL seems to be at odds with the German law. Last time I talked to RMS I asked him about this and he told me that it's a non-issue. For the Germans: You may want to get this book Open Source Software
von Till Jäger, Axel Metzger
