In principle, circumventing DRM does indeed violate copyright law (or rather the German version thereof). However, there's also the right to make private copie

In principle, circumventing DRM does indeed violate copyright law (or rather the German version thereof). However, there's also the right to make private copies, and I'm not aware of any relevant case law. Keep in mind that this is civil law, and "Wo kein Kläger, da kein Richter" ("No plaintiff, no judge").