Major ongoing stories, especially sensational ones like a new epidemic, lead to tons of copycat and follow-up posts. In order for the front page not to fill up with coronavirus stories, or some other sensation du jour, we try to downweight follow-up posts unless there is significant new information. Otherwise the threads fill up with repetition of what's already been said, wild speculation, or both.

We hit on the "significant new information" test after the Snowden storm of 2013, when users justly complained that the front page had become inundated with too many articles that added nothing substantial and were just triggering repeat threads. As a discussion becomes repetitive, it also tends to become wilder and more flame-prone—as if the mind has to resort to that to amuse itself, since there's nothing new to sink its teeth into.

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https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que...

Since HN's organizing value is intellectual curiosity, repetition and groundless speculation are among the things most to be avoided here. That's why we moderate that way.