My close friends know where I stand. I've posted a few things on FB though haven't changed my religion status to Atheist. So pretty much everybody should know. I dont make critical comments if they post religious stuff, though there have been a lot of prayer for Japan type posts recently.
My family should know because Ive said more than once; but one brother, who became more religious recently, seems to ignore what I said and still engages me as if we have belief in common. It is odd.
In general I'm at a point in my personal life that I've self selected out of any group where it would really be a problem.
Facebook is an interesting and somewhat dismaying experience, particularly if your profile says that you are an atheist. People with whom I haven't had contact in decades feel it's their right to lecture me about my "evil life" without god. There are also others, usually ministers, that want to become Facebook friends so that they can try to save my soul.
I rarely log into Facebook these days. The numerous postings that want me to click like "if I believe jesus is lord" are just too annoying.
It would be nice to know like-minded individuals on Facebook.
OMG. So then my Uncle Joe, the orthodontist, was right? Dentists ARE taking over the world!