In June 2014, Harvard Law scholar Jonathan Zittrain wrote an essay in New Republic called, “Facebook Could Decide an Election Without Anyone Ever Finding Out,” in which he called attention to the possibility of Facebook selectively depressing voter turnout. (He also suggested that Facebook be seen as an “information fiduciary,” charged with certain special roles and responsibilities because it controls so much personal data.)

In late 2014, The Daily Dot called attention to an obscure Facebook-produced case study on how strategists defeated a statewide measure in Florida by relentlessly focusing Facebook ads on Broward and Dade counties, Democratic strongholds. Working with a tiny budget that would have allowed them to send a single mailer to just 150,000 households, the digital-advertising firm Chong and Koster was able to obtain remarkable results. “Where the Facebook ads appeared, we did almost 20 percentage points better than where they didn’t,” testified a leader of the firm. “Within that area, the people who saw the ads were 17 percent more likely to vote our way than the people who didn’t. Within that group, the people who voted the way we wanted them to, when asked why, often cited the messages they learned from the Facebook ads.”