Maybe the problem isn't that Facebook distorts life, but that reflects it all too well.
The real dangerous reshaping work of Facebook, and other sites that reproduce race, class and ideological divides, is that it reinforces the real world's inequality and distrust. Peeling back the myth of the Internet as Ultimate Equalizer, we see discrete digital worlds where people from different backgrounds are separated by brick walls of code. The problem isn't that Facebook makes us white-washed, disingenuous, self-promoting nodes. It's that white-washed, disingenuous self-promotion translates, in our society, to success.
What's a "good" Facebook profile? What are the standards we're seeking to meet when we untag pictures, select bands and films and quotes? Some version of our "best selves," sure — but according to whom? For whom? As Gordon points out, the network of "friendship" is not generally strangers — it's the same loose circle of people whom you might meet fleetingly in the real world; now there's just a record of it, and the number of friends becomes not a measure of popularity so much as organization, ambition, and faith in the still-obscure powers of "social networking."
If you're involved in social networking at all, however nominally, you're participating in this experiment. Really, when you think about it, there are two approaches to the medium: defensive — those who seek to limit information for that worst-case scenario future-employer — and the others, who deliberately craft an image to impress or intimidate exes or future friends. Which is glass-half-full and which the more negative is an interesting question; both are cynical in their own ways. And at the end of the day, whatever we choose becomes quick short-hand not just for our tastes or opinions about a candidate or what we think is funny, but who we think decides these things. Writers sometimes talk about "who" they're writing for — even in the context of private journals. When the medium's public, the question seems simpler, but in other ways maybe it's even more fraught.