Hmmmm. My cat Rutger had an account on FB for many years. In fact, I listed him as my "In a Relationship With," and he had many friends although I kept forgetting his password, so he didn't keep up with flame wars or witty reparté.

alicey's dog Truffle has an account.

And come to think of it, the one kid who still maintains a Boomerbook account doesn't use his own name. Though he did once, so maybe the linkage is still there. I dunno.

Long way of saying FB is terribly selective about which people it goes after for phony profiles.

I use my own name there but I tell them I live in Turkey and was born in Bulgaria. You don't have to provide them with any relevant info about your life. And it's a good way to keep in touch when your network is particularly far flung.