Data protection officials in Germany have won a stage victory over the Internet giant Facebook and its head Mark Zuckerberg. Responding to official complaints, the company has agreed to make far-reaching changes to its controversial "Friend Finder" service.

Until now, people have received e-mails inviting them to join Facebook, even if they had never before had anything to do with the social network. Particularly disturbing for many of the recipients of such invitations, the mails often included images of people they knew.

"For many, it wasn't clear at all how Facebook could know that they knew certain members of the social network in real life," says Johannes Caspar, who handles data protection issues for the city-state of Hamburg. In response to the concerns, his office initiated proceedings against Facebook.

Of particular concern was the methods the social network used to acquire new members. If a Facebook member allowed to company access to his or her e-mail address book, the platform was able to use that information to send out invitations to potential new members.

'Transparent Control'

In negotiations with Hamburg data protection officials, Facebook has agreed to provide every member "transparent control over the addresses he or she imports" into the network. An address book is to be provided which enables the user to choose who on the list should be sent an invitation to join Facebook. Warnings are also to be shown when users load their address book into Facebook or when an invitation is to be sent.