> HN doesn't have very strong moderation

FWIW, I agree. But the people who are shadow banned for trivial offences would probably be writing replies to your comment about this ... if they knew they were shadow banned that is. And we wouldn't be able to read it either way, so it's a moot point. Just one data point, but one of my friends has been shadow banned from HN for years and he never even knew that he was. Say what you will about twitter and Facebook, but at least they're up front about bans.