Fact-checkers and journalists try their best to surface facts, but there are just too many lies and too few of us. How often the average citizen falls for fake news is unclear. But there are plenty of opportunities for exposure. The Pew Research Center reported last year that more than two-thirds of American adults get news on social media, where misinformation abounds. We also seek it out. In December, political scientists from Princeton University, Dartmouth College, and the University of Exeter reported that 1 in 4 Americans visited a fake news site—mostly by clicking to them through Facebook—around the 2016 election.