They're very popular in the auth left spaces of reddit (and some that claim to not be auth left but that's a convo for another time)

You'll get banned for having a post history or comment history in the wrong subreddits the first time you try to make a post or comment

Funnily enough most of the right wing subreddits I tested (I was really bored) didn't have those bots firing off

Of course I did my testing last year, but I doubt it's changed