How marginalized groups use Twitter to advance counter-narratives, preempt political spin, and build diverse networks of dissent. The power of hashtag activism became clear in 2011, when #IranElection served as an organizing tool for Iranians protesting a disputed election and offered a global audience a front-row seat to a nascent revolution. Since then, activists have used a variety of hashtags, including #JusticeForTrayvon, #BlackLivesMatter, #YesAllWomen, and #MeToo to advocate, mobilize, and communicate. In this book, Sarah Jackson, Moya Bailey, and Brooke Foucault Welles explore how and why Twitter has become an important platform for historically disenfranchised populations, including Black Americans, women, and transgender people. They show how marginalized groups, long excluded from elite media spaces, have used Twitter hashtags to advance counternarratives, preempt political spin, and build diverse networks of dissent.