I have two Facebook accounts, both male, but one is for people who knew me from before. I would love to collapse everything into one account, but my old friends WILL occasionally post trans-related stuff on my wall with "thought you'd like to see this" types of comments. And a huge percentage of my "before" friends are trans, many of them visibly so.
I was always worried that my two worlds would collide. Now I just don't FB, and I'm much happier. The accounts are still there, but I don't do anything with them.