Buffett: "One of the things we try very hard to do at Berkshire, is to stay within what I call our circle of competence."[1] It would surprise me greatly if the social network sphere is within Buffett's circle of competence, and it would surprise me even more if he thought it was, and so I would interpret his comments about it accordingly.

[1] http://seekingalpha.com/article/148662-circle-of-competence-...