ABSTRACT
Social networks are platforms that allow people to publish details about themselves and to connect to other members of the network through links. Recently, the population of such online social networks has increased significantly. For instance, Facebook now has close to a billion daily active users (see https://newsroom.fb.com/Company-Info/). Facebook is only one example of a social network that is for general connectivity. Other examples of social networks are LinkedIn (professional), Last.fm (music), orkut (social), aNobii (books), and the list continues.
