Multiparty Privacy in Social Media

OVER TWO BILLION users consume social media to build and participate in online social networks (OSNs), uploading and sharing hundreds of billions of data items. 15 OSNs are not only huge in scale, they are predicted to keep growing in the coming years both in the number of users and in the amount of data users upload and share. The vast amount of data in social media is user-generated and personal most of the time, which clearly calls for appropriate privacy preservation mechanisms that allow users to benefit from social media while adequately protecting their personal information. Protecting users' privacy is not only essential to respect the Universal Declaration of Human Rights but also to serve as a first line of defense to mitigate cybercrime and other illegal activities that leverage the data obtained due to privacy breaches in social media, such as social phishing, identity theft, cyberstalking, and cyberbullying. There have been many efforts devoted to study privacy in social media and how to protect users' personal