Facebook has lost the first round of legal action against alleged German copycat site StudiVZ.
Facebook has accused StudiVZ of intellectual property theft and taken the matter to court in Germany and the US.
The US case is still underway, but German judges at the County Court in Cologne have ruled against Facebook, according to media reports.
The court found that StudiVZ does not pretend to be Facebook, which was virtually unknown in Germany when StudiVZ was launched in 2005, and that Facebook's lawyers had failed to prove allegations that StudiVZ stole Facebook's source code.
StudiVZ for students and its spin-off sites for schools and general users have over 12million German-speaking members, roughly six times more than Facebook.
Some commentators have said the German court rulingis good from a policy perspective because it is aimed at letting sites compete on merit, rather than worrying about who copied what from whom.