Social media platforms are the latest manifestation in a series of sociotechnical innovations designed to enhance civic engagement, political participation, and global activism. While many researchers started out as optimists about the promise of social media for broadening participation and enhancing civic engagement, recent events have tempered that optimism. As this book goes to press, Facebook is fighting a battle over the massive disclosure of user information during the 2016 U.S. presidential campaign, social analytics company Cambridge Analytica is being revealed as a major player...