Abstract

Abstract. Web 2.0 and Social media have widened society’s opportunities for communication amusement and networking, while enabling internet users to contribute online content. The information flows created, along with Open Source Intelligence techniques, can be crawled and processed for a variety of reasons from personalized advertising to behaviour prediction/profiling. In this paper, our goal is to present two horror stories from the digital world of Social Media, in order to: (a). Present an insider threat prediction method by (e)valuat-ing a users ’ personality trait of narcissism, which is deemed to be closely con-nected to the manifestation of malevolent insiders, as it was developed via Twitter. (b). Raise user awareness over political profiling and data processing for discriminative purposes, via a methodology applied to YouTube. As both methodologies set user’s privacy and dignity at stake, we provide the reader with an analysis of the legal means for each case, so as to effectively be prevented from a privacy violation threat and also present the exceptional cases, such as the selection of security officers of critical infrastructures, where methodologies to detect the insider threat could be used.