This chapter traces the formation and growth of Anonymous, a loosely organized “hacktivist” group, which first appeared in major news outlets in 2008 after it targeted the Church of Scientology. It discusses the group’s strategies and involvement in various political issues, including the Arab Spring and the 2016 United States presidential election. Despite disagreement about the nature of the collective, the chapter analyzes its contentious actions and considers whether it meets the criteria established earlier in the book for a social movement organization.