Social Networks are popular Internet services that are heavily frequented. With 400 million active users, Facebook is the biggest of these communities on the Internet. The experience shows that the inhibition of the users to publish personal content within these networks and to thereby make them permanently available to everyone, is very low. At the same time, the user practically loses control over the content provided by him, as it can be saved and copied without his permission or even knowledge. This article shall discuss the limits of reliability on the example of Facebook, with special emphasis on the use of text and images from social networks in the media.