It's especially curious, because HN does try to have a free speech uber alles approach. If limiting speech is good for HN, why isn't it good for Imzy?
It's also important to remember that reddit is very pro-free speech, but bans some protected speech, namely, doxxing. Redditors started to dox people who ran some of the more ahem controversial subreddits. And then reddit banned doxxing.