On-line Social Networks (OSN) have become a central point of the Internet. Hundreds of millions of users interact daily on the OSNs, producing and consuming large amounts of user generated data. The importance of the OSNs in the political discourse was promptly recognized during the 2008 USAs presidential campaign, where the usage of the digital communication channels by the democrats was one of the differential characteristics. Since then, OSNs have been recognized as an important channel to reach the target group and as a source of a trove of user generated information.