A German privacy watchdog has told Facebook it can’t stop people using ‘unofficial’ names.

Facebook’s insistence people use ‘real’ or ‘legal’ names has been criticized for making life difficult for trans people, drag queen performers and others.

Now the Hamburg Data Protection Authority, responsible for ensuring organizations comply with German laws on personal privacy, has entered the argument.

It ruled Facebook could not unilaterally change users’ chosen usernames to their real names, nor could it ask individuals to provide official ID.

The German order follows court action on the part of the Belgian privacy watchdog in June in respect of how Facebook tracks user activities. The German and Belgian authorities are now working with Spanish, Dutch and French counterparts to review Facebook’s privacy policy.

The ruling follows a complaint from a woman whose Facebook account had been blocked on the grounds she used a pseudonym. Facebook unilaterally changed her username into her real name, and demanded a copy of her ID before changing it back.

According to the Hamburg Data Protection Authority the woman did not want to use her real name to avoid being contacted through it for business matters.

Clarifying its ruling, it explained that forcing users to use their real names violated their privacy rights.

The authority only covers the city and state of Hamburg but its ruling reflects tough federal laws on privacy. Facebook’s policy could well be interpreted in the same way by other federal states.

Facebook replied it was disappointed with the order and that German courts had reviewed their policy on many occasions and deemed it compliant with EU law.

A spokesperson said: ‘The use of authentic names on Facebook protects people’s privacy and safety by ensuring people know who they’re sharing and connecting with.’

In 2013, Facebook successfully overturned a similar ban on its real names policy, imposed by the Data Protection agency in the northern state of Schleswig Holstein.

At the time, a state appeals court confirmed a lower tribunal’s ruling that German privacy laws don’t apply to Facebook because the social networking site has its European headquarters in Ireland, where privacy rules are less stringent.

Facebook continues to claim that as its European headquarters are in Ireland it should only abide by Irish law in Europe and has therefore rejected the jurisdiction of other national authorities.

In December 2011 the Irish privacy watchdog concluded Facebook’s authentic name policy did not contravene Irish law and its reasons for the policy, such as child safety and the prevention of online harassment, were justified.

However Johannes Caspar, the Hamburg Commissioner for Data Protection, rejected the argument that Facebook should only be subject to Irish data protection laws.

He said: ‘Facebook cannot again argue that only Irish Data Protection law would be applicable… anyone who stands on our pitch also has to play our game.’

His decision has been welcomed by Richard Koehler, Transgender Europe’s senior policy officer.

Koehler told GSN: ‘Yesterday’s decision is very encouraging as it strengthens the right to self-determination and privacy in an increasingly interconnected world with at times overpowering global actors.

‘Requesting trans people to reveal names as on ID documents is cruel and ignorant of the fact that many states don’t even allow them to change ID, or require sterilization, a mental health diagnosis and/ or divorce to do so.

‘Facebook should immediately stop its “real name” policy that pushes trans and gender variant people out of the net for alleged identity fraud.’