[flgr]

Interestingly, Facebook's algorithms also reward activity which has the effect of bubbling up group posts with a lot of drama.

[NotaSockPuppet8]

Facebook's algorithms are far less transparent and outside a user's control compared to 4chan's bump system.

Just recently it was shown that their automatic news feeds promoted fake news articles.

[gonehome]

I think this is just how stories get more attention naturally.

For a more detailed explanation: http://slatestarcodex.com/2014/12/17/the-toxoplasma-of-rage/