Facebook's Find-a-Friend emails have got the social network in trouble, as a German court has ruled them illegal.
The feature accesses users' email address books and sends invitations to contacts who aren't yet signed up to Facebook.
However, this has been deemed illegal by Frankfurt's Federal Court of Justice, who labelled the function an intrusive form of marketing.
"Invitation emails from Facebook to people who have not clearly consented to receiving them are an unacceptable nuisance," the court ruled, after upholding a previous ruling by a lower court.
The tech giant is now obliged to disable the Find-a-Friend feature in Germany. A spokeswoman for Facebook stated that the company would review the ruling as soon as it is available in full.
"We will study it carefully to assess any impact on our services today," she said.
Last year, ​Facebook faced more scrutiny over its privacy practices in Europe, after users accused the site of unlawfully tracking them even after they have logged out of its services.