I think social media is a somewhat relevant corollary, where it self-polices content.

I'd say sometimes--like HN--it's a success. Good behavior is encouraged & enforced. Bad behavior is punished.

Other times--like reddit--not a success. The hive-mind is real there, and in particular well-mannered disagreement that is misaligned with the norm is punished pretty strongly there.

Plus we all have heard how their investigations of real-life events have turned out--witch hunts.

I think reddit's population is more reflective of the general population, unfortunately. I don't think self-policing would end well at all.