I don't know if it's marketing or something else, but pop-tech books all seem to get slotted into the "tech is going to make us unto gods" or "tech is killing our souls" buckets. I'm pretty sure Turkle's work is more subtle than that, but she certainly seems to fall in the latter category here. Other recent entrants in this genre include Jaron Lanier (reviewed here), Andrew Keen, and Nicholas Carr. I find this irritating and simplistic. Why do the effects of technology have to be good or bad? Can't they simply be different?
So, what is it about the performance aspect of Facebook that might be objectionable? Well, for one thing, it's a much less subtle, less rich medium than face-to-face communication. F2F performances can be improvised, adjusted to situations, respond to the performances of others in an intricate dance. Performing on Facebook or Twitter is by contrast a rather crude affair (for instance, there's no analog for eye contact), which tends to degenerate into trivia and naked self-advertisement. You have far less control over context -- most of the problems with Facebook seem to revolve around how it collapses social contexts into a formless blob, resulting either in embarassment (if you allow stuff to escape from its proper context) or repression (if you limit yourself to interaction that is appropriate for every possible audience)*. This however is not a new problem:
Socrates: Writing, you know, Phaedrus, has this strange quality about it, which makes it really like painting: the painter's products stand before us quite as though they were alive; but if you question them, they maintain a solemn silence. So, too, with written words: you might think they spoke as though they made sense, but if you ask them anything about what they are saying, if you wish an explanation, they go on telling you the same thing, over and over forever. Once a thing is put in writing, it rolls about all over the place, falling into the hands of those who have no concern with it just as easily as under the notice of those who comprehend; it has no notion of whom to address or whom to avoid. And when it is ill-treated or abused as illegitimate, it always needs its father to help it, being quite unable to protect or help itself.Facebook and Twitter identities are a strange mix of oral and written communication styles. Frankly, it's way too early in the evolution of digital social networks, or whatever you want to call them, to say what they are ultimately going to do to our souls.
I give Turkle a lot of credit for being one of first humanist-type people to take the sociology of digital technology seriously. Now of course that's a whole industry, but she has been at it for decades. Unfortunately, getting old in this world may mean you can't keep current with what the kids are up to these days (as a youngish greybeard myself I am acutely aware of this problem). I'm pretty sure that the critics are right and the displacement of traditional media by the digital world entails the loss of some valuable things. But obviously it also creates a great many new and wonderful things, most of which have yet to be invented. The human soul and persona will adapt to them as it always does.
*[update: this was written before Google+ Circles came along to "solve" this problem. Why that don't actually seem to help will have to be a topic for another post.]