Peer-to-Peer Social Networks

In the last ten years, the pervasive adoption of social networking sites has deeply changed the web. Social web sites have attracted users with very weak interest in technology, including people that before the social networking revolution were not even regular users of other popular Internet services and computers in general (Stroud, 2008). The phenomenon is so widespread that many people started using social networking systems to ask questions directly to people instead of querying search engines (Morris et al., 2010) and in place of regular email. Moreover, some of the largest social networking sites constitute a separate and closed network (Sabbag, 2011). After the huge success of the early social networking systems, many other players came in the social networking market and nowadays hundreds of different social networking systems exist. Even if the social networking systems are greatly dissimilar in their user base and functionality, they are almost always centralized systems. The centralized nature allows a simple browser-based user experience and, moreover, many algorithms, e.g., friend suggestion, are far easier and more efficient to implement in this setting. However, it also presents many drawbacks, e.g., lack of privacy, lack of anonymity, risks of censorship and operating costs. The goal of this chapter is to briefly introduce social networks, to show their relationships with peer-to-peer and multi-agent systems, and to discuss about the use of peer-to-peer and multi-agent systems in development of social network systems.