Last week, on a conference call with reporters, Mark Zuckerberg, the C.E.O. of Facebook, began, uncharacteristically, with an apology. “For the first decade, we really focussed on all the good that connecting people brings,” he said. “But it’s clear now that we didn’t do enough. We didn’t focus enough on preventing abuse.” He added, “That goes for fake news, foreign interference in elections, hate speech, in addition to developers and data privacy. We didn’t take a broad enough view of what our responsibility is, and that was a huge mistake.” Taken alone, any of the incidents he alluded to—the exploitation of Facebook data by the political consultancy Cambridge Analytica, Russian meddling in the 2016 election, the uptick in viral hoaxes and propaganda—might, eventually, have been forgiven. Taken together, though, they’ve…