Serious trolls know about hellbanning and how to figure out whether an account they're using has been hellbanned. The primary effect of hellbanning is to drive away well intentioned new users who are unlucky enough to break some of the unwritten rules in their first few posts.
This is all very hand-wavy. First of all, hellbanning is not always the same thing everywhere, so no, there's no guarantee that a serious troll knows how hellbanning works. More importantly, I have actually had to deal with forum trolls as an under-resourced dev for a very popular and long-running forum. It's an arms race, plain and simple. Information asymetry is to the developer's advantage. Have I gotten to the point of implementing hellbanning? No... but I understand the justification for why it's done.
How do you know this? Have you run a forum or community website, or have you been on the other side? Serious question. Must know data and provenance of data.
