Who the fuck cares about Facebook?
Facebook is a despicable company that doesn't have even a basic level of respect for its users. This has been readily apparent to anyone who has been willing to look for the better part of a decade. You want to be a part of that? Go right ahead. Just don't act all indignant when they arbitrarily lock your account or sell the data they have on you to corporations or the government.
Furthermore, likening Facebook to a public square is just silly. Public squares don't fight for your clicks by targeting you with advertisements. Public squares won't track every move you make on the Internet after you leave. And, most relevant of all, public squares are places where it's perfectly acceptable to remain anonymous through the use of any pseudonym you can dream up.
I say let Facebook do whatever they want. The more egregious the abuse, the more likely another clueless user will wake up and boycott that shit.