<https://scroll.in/latest/868113/facebook-tests-downvote-feature-for-some-users-in-the-united-states>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://scroll.in/latest/868113/facebook-tests-downvote-feature-for-some-users-in-the-united-states>