Feb. 17, 2021 Credit...Damon Winter/The New York Times A decade ago, the consensus was that the digital revolution would give effective voice to millions of previously unheard citizens. Now, in the aftermath of the Trump presidency, the consensus has shifted to anxiety that onlinebehemoths like Twitter, Google, YouTube, Instagram and Facebook have created a crisis of knowledge — confounding what is true and what is untrue — eroding the foundations of democracy. These worries have intensified in response to the violence of Jan. 6, and the widespread acceptance among Republican voters of th...