A German consumer group has warned users not to use Facebook if the social-networking company fails to withdraw the proposed changes to its privacy policy. Last month, Facebook announced that it was considering changing its privacy policy to allow information to passed on to third-parties without users giving their consent.

VZBV, an umbrella organisation representing consumer groups across Germany, has said that the American company has "repeatedly and deliberately crossed data protection boundaries" and that uses of the worldwide service should be looking to boycott it.

And the group has a high-level supporter, earlier this week German consumer minister Ilse Aigner wrote an open letter to Facebook founder Mark Zuckenberg complaining about the proposed changes and threatened to cancel her Facebook page. ""Private information must remain private," she said.

Now, ZBV wants to get tough with Facebook. According to VZBV director Gerd Billen, "responsibility for data protection lies with the provider not with the user."