Also see the "The Circle", a recently-published dystopian novel by Dave Eggers about a social network of the same name.

The story/plot/characters are meh, but I give it 5 stars for provoking thoughts about hyper-connectedness, net neutrality, surveillance, over-sharing on social networks, the ubiquity of technology, etc.

http://www.amazon.com/The-Circle-Dave-Eggers/dp/0385351399