On Voat, it would have to be the SDBH raids. Or really anything that rustled their collective jimmies.
He was a Voat user who appeared a few weeks after the fist big influx of users there, and spammed a lot of the default subs with anti-Jewish stuff. This was before the Reddit hate sub users turned up and back then it was funny, rather than it being the norm. He would appear on completely unrelated posts and reply with comments that miraculously managed to shift the conversation towards pesky Jews no matter what the topic was.
Eventually he had so many alts, and there were so many other users either imitating him or spreading their own Jewish stuff that it became impossible to tell who he was anymore, or even if he was still using the site at all. He became an anti-Semetic god unbound by accounts or usernames.
I'll add that he had a style that would antagonise the people that agreed with him most. There were conspiracy theories amongst the mouth breathers that he was a JIDF operative.
I sometimes miss sparring with him. Nobody has threatened my families life in over a year. At one point he put out. $50 bounty on 4chan to dox me. They just laughed.
I actually had a list of his alts that I started in the early days when he was still common sense warrior. By the end I had exceeded character limits for the initial post and maybe the follow up comment. And although it was the most comprehensive ever compiled (as far as I know) it was not nearly all of them.
I'm entirely unfamiliar with this fellow. What did he/she do? Sounds...entertaining.