"At its bare essentials, a social network consists of three or more entities communicating and sharing information. This could take the form of a research coalition, a Girl Scout troop, a church, a university, or any number of other socially constructed relationships" (Morrison, 2008).
Looking at the bare essentials of a social network, Facebook falls along the same lines as a church group or health club. Many of those that I communicate with on Facebook are my 'Facebook friends'. Although I knew them in previous social settings, I currently don't see or communicate with them in any other format.
"[In the wake of t]he mass murder at Virginia Tech on 16 April 2007...students and peers notified each other via e-mail. [Other] students at other schools used Facebook to ascertain the status of their friends..." (Morrison, 2008).
Like those affected by the Virginia Tech mass murder, my circle of Facebook friends communicated tragedy by the same means. A dear friend of ours from high school was found murdered in SF last week. The acknowledgment of the tragic event, the consoling, the announcement of the memorial fund, the posting of memorable moments and pictures, and the invitation to the memorial, all took place on Facebook.