Oh I don't doubt that. I'm referencing the fact that some subs will run a bot that checks your post history and will ban you if you have previously posted in a sub they don't agree with or like.

I've personally been "mass-banned" from a string of local sub reddits because I had an argument with a mod about the weather. (not global warming, literally about humid vs dry heat)

I am very politically aligned with the reigning opinions in the sub centered on my hometown/nearest urban centre. Nonetheless I managed to get shadowbanned for reasons that remain unknown to me. Being that that is the only place where local matters get discussed, that was the beginning of the end of my relationship with the site; any place where whoever happened to get there first is able to erase whomever they want with no accountability is a non-starter as a public square of any sort.