Data protection officials in Germany have demanded that Facebook destroy its entire archive of files based on facial recognition technology, accusing it of breaking European laws by compiling a vast photo-database of its users without their consent.

The demand follows the reopening of an investigation that was suspended in June of this year, after German authorities failed in their efforts to get Facebook to comply with its laws.

According to The New York Times, the German’s complaint is that the social media network uses analytical software to compile archives of human faces, which are taken from images upload by users onto their Facebook profiles. One use of this is that it allows Facebook to ‘put names to faces’ with its Photo Tag Suggest feature. The problem is that Facebook’s collection of images is illegal in Europe, where data protection laws state that users have to give explicit consent for their images to be used in this way.

Rather than ask permission to use people’s images, Facebook instead uses a kind of reverse opt-in system, assuming that users will automatically want to make use of facial recognition – anyone who doesn’t has to muddle their way through Facebook’s web of privacy options to opt out.

Johannes Casper, Germany’s data protection commissioner, is now demanding that Facebook “destroys its photographic database of faces collected in Germany and revise its Web site to obtain the explicit consent of users before it creates a digital file based on the biometric data of their faces.”

Facebook, whose recent acquisition of Face.com shows how determined they are to make better use of facial recognition technology, is unlikely to bow to these requests – or at least, not without a fight. The social media network claims that what it’s doing is perfectly legal in Ireland, where its European data servers are based. In a statement to the New York Times, Facebook insisted that “the Photo Tag Suggest feature on Facebook is fully compliant with EU data protection laws.”

Facebook goes on to say that following discussions with the Irish Data Protection Commissioner, it has instead agreed to notify users through Facebook about the facial recognition data it collects on them.

Given that it looks like neither side is going to back down, a protracted court battle may well be on the cards, with Facebook facing either a substantial fine or a court order that forces it to change its practices.