Dr. Efstathios Stamatatos received the diploma degree in electrical engineering (1994) and the doctoral degree in electrical and computer engineering (2000), both from the University of Patras, Greece. He has worked at the Polytechnic University of Madrid (1998) as a visiting researcher, the Austrian Research Institute for Artificial Intelligence as a post-doc researcher (2001-2002) and the Technological Educational Institute of Ionian Islands (2003-2004) as an assistant professor. Since 2004 he is a faculty staff member of the Department of information and Communication Systems Engineering, University of the Aegean (currently as an assistant professor). His research interests include text mining, natural language processing, information retrieval, and machine learning. He is the director of the Artificial Intelligence Lab., University of the Aegean, and has participated in 11 research projects funded by Greece or the European Community. Dr. Stamatatos has co-organized several international workshops and scientific competitions on plagiarism detection, authorship attribution and social software misuse.