Facebook will eventually become part of what philosopher Martin Heidegger would call the background of everydayness -- something that simply "is." And some people will really like it, and it will provide them with the kind of social interaction they are incapable of getting from the three-dimensional world around them. And some people will turn it off, never to bask in its glow again.
Heidegger, of course, would say that such things destroy authentic place and time. Cf. his comment on radio in Being and Time (omitted by Macquarrie & Robinson, but included in the Stambaugh translation).
The bit about the radio rang a bell. I found it went by four years ago.
I am still un-Facebook-ed (my wife keeps me up-to-date on friend and family baby pictures through her account), but I discovered I had to have a LinkedIn account to "exist" when I last changed jobs.