Today, with the fast changing technology and life-style, online social networks (OSNs) play an important role in everybody's life. Online social networking has made a drastic change in the way we pursue our social life. At the same time, various security problems like fake profiles, online impersonation, socialbots, clickjacking, identity clone attacks, publish spam messages, etc have also grown. Moreover, the concept of applying a computational intelligence (CI) approaches in social network analysis is feasible and sound. Therefore, the papers of this special issue address variety of security and privacy issues in online social networks including, social network modelling and security issues, information revelation and privacy, mining and analyzing social data, social networking data analysis tools and services and security of other aspects of online social networks.