I used to be a member of several local forums that are not English. When issues started like there were trolling and ranting I felt bad about the forum and left. Now I am into 3 English forums and I think that is the appropriate number for me.
I'm on lots of different forums, but honestly I'm only active on a handful these days. Two of them I've been a member on for over a decade now actually. I wish I had more time to actually log into most of the forums I've been a member on and post. I might actually get around to popping back into some of the forums I haven't logged into in a long time, just to see how people are doing. (I did so recently with Chatting Time actually...)