The interaction between community mechanics and the resulting political structures (e.g., "threaded vs. nonthreaded comment sections", "the effects of various moderation systems", various methods of giving out higher levels of privileges, etc.) has been a minor hobby of mine for ~15 years. Here's one result I've noticed: Once you introduce scale into a community, in that way that only the Internet really can, you encounter certain major problems such that you end up with only two choices: Literally permit everything up to and including child porn and every other kind of skeevy thing ever, or engage in curation policies that somebody will, with a straight face, call censorship. And it's not the obvious connection you'd think, either. It's not that "removing child porn" will be called censorship (it will, but not by people that very many other people care about), it's that you end up with a certain choice, and the result will inevitably be "censorship" by somebody's accounting, and it'll probably be a reasonable claim from many points of view.

Imagine you have a landscape of statements that could be made. Color some of it black for being unacceptable by your standards, color some of it white for being perfectly acceptable. No matter how you slice it, there's some grey frontier in between. Throw a dart for every statement made by, say, 10 people in a week. A gentle smattering of darts appears. Maybe only a handful of statements will even be close to that grey line, and none of them land on it. Now throw a dart for every statement made by ten million people in a year. The landscape is no longer visible under the mass of the darts. Now tell somebody they have to go on to the field and clear out precisely and exactly the statements that are "on the dark parts". It doesn't matter how you slice it... someone's gonna scream about how their message was removed.

And that metaphor implicitly includes the idea that we all agree on the colors. In reality, of course, we all wildly disagree, even if there are broad patterns within certain cultures that can be seen. [1]

The only two simple solutions to that problem, "allow everything" and "allow nothing" are respectively illegal (and at least arguably unethical), and pointless (what's a community that allows 0 communication internally? I suppose one of those crazy logic puzzles about hat colors and wardens shooting prisoners. But that's about it.).

This theory predicts that all communities at scale will have a set of people complaining about how it censors. This is more than just HN or Reddit, but anything, NYTimes, Usenet, a sufficiently large GitHub project, everything that doesn't literally allow everything. I'm not aware of any counter-example....

So, given that it's impossible to have a scaled community that doesn't have people accusing it of censorship, it doesn't seem all that interesting to abstractly accuse one of it. One would have to criticize it from a more specific point of view, like, is the stuff being removed significantly at odds with what the community it represents expects? Or is there perhaps an ethical standard that you'd like to specify that is more specific than merely "shouldn't 'censor'" that you'd like to discuss? That's a serious question, BTW; I am not merely defending HN as a status-quo defender. Of course, the ethical standard will itself be up for debate. So it goes.

[1]: Standard metaphor warning: Don't argue the metaphor. It's just a metaphor. Neither the landscape, the colors, nor the darts exist, so there's no way they could "really" have three colors or "really" be nasty fractals or "really" anything else. Argue about the point it's making.