@lauren @pingle Funny coincidence. Researching this question and learning about the tools available for dealing with bad actors is on my to-do list. I was already engaged in it and in conversation with the admin of my instance when your post showed up. (Creepy, huh?)
I've not run into a problem yet but I'm sure I will eventually. I know there are bad instances on Masto. When I first started on Mastodon four years ago I went searching for trouble and found it. So I know it exists. Now I'm going to flesh out my knowledge of all levels of this issue. I'll write it up if it seems worthwhile.