“In place of free-for-all Twitter hashtags—which, valuable as they are in creating an unfiltered channel for communication, are often cluttered with ephemera, re-tweets, and other noise—they give us editorial order. And in place of dubious sources—users who may or may not be who they say they are, and who may or may not be worthy of our trust—the lists instead return to one of the foundational aspects of traditional newsgathering: reliable sources.”