The emergence of the Internet has profoundly affected many spheres of human life. Thanks to advances in telecommunications, it is now possible to stay connected to the Internet around the clock, and share experiences with other users in real-time. Many services have been established to help exactly that cause, and they commonly come in the form of social networks. The abundance of content publicly available via these networks motivated researchers to devise new methods for its analysis and extraction of patterns and knowledge hidden in it. Data mining, as a way of automatic - or more commonly...