This weekend—after a horrific mass shooting in New Zealand was live-streamed on Facebook—we’re bringing you a selection of pieces about the ways in which social media is affecting our lives and our politics. In “Ghost in the Machine,” Evan Osnos investigates Facebook’s impact on the 2016 Presidential election and assesses the social network’s efforts to balance freedom of expression with content moderation; in “Antisocial Media,” Andrew Marantz chronicles Reddit’s attempt to fight hate speech. Adrian Chen traces the journey of Megan Phelps-Roper, the granddaughter of the founder of the Westboro Baptist Church, as she becomes more active on social media and eventually transforms from a faithful adherent into a skeptic, in “Unfollow.” Ariel Levy visits Ohio and examines the role of online vigilantism in a rape case in the town of Steubenville, in “Trial by Twitter.” In “Beauty Is Justice,” Jiayang Fan describes how the selfie phenomenon and innovative photo-editing apps are changing the ways in which people perceive individuality and beauty in China and across the globe. Finally, in “Man and Machine,” Susan Orlean delves into the surreal world of the Twitter account Horse_ebooks and its experimental approach to Internet art. At a time when social media is transforming seemingly every aspect of society, these pieces take its measure.