A German court has declared the Facebook "find a friend" feature illegal. In a shocking decision, the Federal Court of Justice slammed Mark Zuckerberg's firm for sending out emails inviting people's friends to join the social network. This means Facebook could be forced to stop sending these messages, which are designed to woo users' chums into signing up. "Invitation emails from Facebook to people who have not clearly consented to receiving them are an unacceptable nuisance," the court ruled.