A team of researchers led by Andrew Guess of Princeton University tracked the internet use of over 3000 Americans in the lead up to the 2016 presidential election. They found Facebook to be the referrer site for untrustworthy news sources over 15% of the time. By contrast, Facebook referred users to authoritative news sites only 6% of the time.

The authors state, “This pattern of differential Facebook visits immediately prior to untrustworthy website visits is not observed for Google (3.3% untrustworthy news versus 6.2% hard news) or Twitter (1% untrustworthy versus 1.5% hard news).”