In a major blow to big internet platforms, Europe’s top court said Thursday that an individual country can order Facebook to take down posts, photographs and videos and restrict global access to that material—a move that places more responsibility on internet platforms to patrol their sites for content ruled illegal.

The decision by the European Court of Justice means social networks like Facebook will be required to remove defamatory material hosted on their sites if they are aware that the content is harmful to an individual’s reputation. It also means national authorities can ask social networks and other platforms to take down material that has been judged to be defamatory or “equivalent” to defamatory content.