After getting a couple of thousand karma points at HN over the course of a year (manly due to a couple of very popular story submissions) I quit going there because their administration is even more opaque than slashdot.
They have this policy of "hell-banning" posters so that they think their posts are going through, but they are the only people who can actually see their own posts. If you set an obscure flag in your preferences you can see their story submissions (and comments), they are marked "[dead]" immediately upon posting rather than by any human process of moderation. I got curious when I noticed five or six people who had been making high quality story submissions for months that were basically invisible to everyone else.
The admins at HN don't notify people when they get hell-banned, they don't tell them what they did wrong so they can avoid it in the future. No warning, nothing. The admins don't even give the people who have been hell-banned a chance to make amends. If they do happen to figure out that they've been hell-banned on their own, there is no process for appeals, nor any other form of remediation.
It's completely arbitrary, capricious and well, Kafkaesque. Kind of like getting on the TSA's no fly list. Nobody will tell you anything and if you figure it out there is nothing you can do about it. I guess the TSA is worse because you can't really change your identity, but you can create a new account at HN. But you still won't know what you did to get hell-banned, you may well do it again. That shit's going to get old after a while.
Once I realized just how cruelly (presumably unintentionally) HN was run, I didn't feel like I could continue to contribute to their success so I took my toys and went home. I really wasn't up to a campaign of trying to fix things, just wasn't worth the effort.