Recent quotes:

A deep look at Google's biggest-ever search quality crisis

A big challenge for search engineers in the past was dealing with overt spam trying to attain high rankings. Now they have to grapple with “post-truth” content where pages that sound factual or informative to an algorithm can be anything but.

Study: Social Media Content Credibility Comes from Sharers, Not Creators

What they found, API Executive Director Tom Rosenstiel said, was that the sharer of the content weighed more heavily in the minds of viewers than its original source. If a Facebook friend is thought of as completely credible, the news they share, even if from a questionable original source, is more likely to be considered trustworthy.