Multiparty Privacy in Social Media

The first research stream proposed support for MP by helping users to identify where MPCs can or did occur.2,39 For instance, Wishart et al.39 present a way to specify strong and weak sharing preferences so that these preferences could be inspected to find conflicts. Also, Besmer et al.2 introduce a system whereby users tagged in a photo can contact the user who uploaded the photo to ask to remove it or to restrict the audience of the photo, which resembles the functionality Facebook introduced some time later.7 While these approaches represented a stepping-stone, recognized the problem of MP, and proposed a partial solution to it, they left all the negotiation process to resolve detected conflicts to happen without any particular technical aid. That is, users must resolve every potential MPC in a manual way, which may become an unbearable burden considering the massive amount of content uploaded and the number of friends that users have in social media.