For the umpteenth time, moderation is not censorship. HN is akin to a private club not a country that you are born into forced to live in. And furthermore, the chaos is anything but unknown. It is mob/troll rule ala slashdot/reddit/4chan and every other online community that grows beyond a critical mass.

To Censor: to examine in order to suppress or delete anything considered objectionable.

So this is censoring speech. They have the right to do it as they're a private entity. But don't confuse their right to censor with the definition of censorship. I see that happen a lot.