When I first started reading this sub it was totally dominated by a guy named u/ideasware. Like three quarters of the content posted here was posted by him. A lot of his focus was evangelizing about the control problem and it was highly polarizing.

I spent tons of time arguing with him daily for a while. At that point I was more optimistic, and he was extremely concerned about the control problem and social upheaval and various angles of AI apocalypse. Now I share many of his concerns. He died four or five years ago, so it was before that.