I didn't get much from Richard Posner's assessment of Facebook in the New Republic -- it's basically a description of what a social network is -- but I thought this was interesting:
A Facebook network is a social collective, a virtual kibbutz, and studies have found that children brought up in a traditional kibbutz have difficulty forming strong emotional relationships as adults.
I wanted to agree enthusiastically, but then I began wondering how "strong emotional relationship" was defined for research purposes, and what sort of normative assumptions were smuggled in with that definition. I have no idea what life is like on a kibbutz; I imagine the ideological indoctrination into collectivity is intense and a major goal of this is to obviate the corruption that can come from "strong emotional relationships" -- I'm thinking of The Blithedale Romance and how the private emotions upset the utopian initiative at Brook Farm. Mark Zuckerburg is grandiose enough to dream that such an indoctrination can spread to the entire world -- at least that's the positive spin on his whole whole "privacy is shady" spiel.
I'd guess that Facebook is like a kibbutz to the degree that it can physically isolate its users and force them to rely on the network as the only channel for friendship. If it convinces you that friendship is a matter of broadcasting an idealized self and bringing in a volume of information exchanges in the network. But private spaces still exist in capitalist society in which intimacy can be detached from the network and hidden intensities can be developed. Far from killing privacy, perhaps Facebook may even sharpen the experience of it, giving intimacy something unmistakable to define itself against.