[J-dawg]

Thanks for asking this. Here's another one that was posted and then disappeared without a trace:

https://www.reddit.com/r/slatestarcodex/comments/6t1cpx/if_w...

[notliketherest]

Hackernews doesn't allow you to "downvote" submissions, but users with higher "karma" can flag posts, effectively giving the most active (or popular) users censoring powering.

[soared]

I think it requires 750 or 1k karma, which isn't a huge amount. I'd image a decent percent (~20%) of users have flagging power.