I moderate a Monergist group on Facebook, made up of Baptists, Presbyterians, Lutherans, even a Mennonite, and we have only ever banned a handful of people. The vast majority of ban circumstances were because the person’s account turned out to be spam, but one guy was banned because he spammed the wall with links to his blog after he was told not to do so. However, we’ve never banned anyone for contrary thought. We had an Arminian gentleman join and engaging us in dialogue, and to my knowledge he’s still a member, though he no longer posts on there much. We also had some Seventh Day Adventists join and ask us questions, and they were permitted to do so without any fear of ban. I don’t know the circumstances around your banning at the particular Baptist forum, but I doubt you’d fear banning from us unless you were disrespectful, posted gross or obnoxious things, or broke general group rules repeatedly.
What kind of Baptists were they, any way?
Regarding CAF, the only people I know who got banned had it happen because they were trolling accounts. I know at least two Muslims who were banned, not because they were Muslim, but because they became insulting to other members (one began calling Roman Catholics “pigs,” the other said demeaning things to female members).