Once, in the pre era before social media—or before smartphones, or the Internet—there was a time when journalists were trusted, Fergus McIntosh, the head of The New Yorker’s fact-checking department, writes. Back then, everybody read muscular daily newspapers and watched straight-down-the-line TV reporting. When citizens had to make political decisions, a robust social contract with the media insured that they were well informed; even if they couldn’t always agree on what to do or whom to vote for, they could rely on a shared set of facts. “But then something changed: people stopped paying attention to the news, or decided that they didn’t believe it anymore. They got distracted by podcasts, Facebook, and Twitch. They became ill-informed, and started to act against their best interests. The media decayed and fragmented, along with the nation. Opinion and news became indistinguishable, misinformation ran amok, and that is how we came to live in the post-truth world,” he continues....