Facebook is Testing a Down Button
CNBC reports that Facebook is testing a down button that allows users to flag and hide comments they think are "offensive," "misleading," or "off topic." They're then hidden from view.
A Facebook spokesperson said: “We are not testing a dislike button. We are exploring a feature for people to give us feedback about comments on public page posts. This is running for a small set of people in the U.S. only.”