This study examines the international activist movement known as Sleeping Giants, a social-media “campaign to make bigotry and sexism less profitable” (Sleeping Giants, n.d.). The campaign originated in the US with an anonymous Twitter account that enlisted followers in encouraging brands to pull their online advertising from Breitbart News. The campaign achieved dramatic success and rapidly spread to regions outside the US, with other anonymously run and loosely allied chapters emerging in 15 different nations (as well as a regional chapter for the EU). Many of these were initially created to take on Breitbart advertisers in their home countries, but in a number of cases they subsequently turned their attention to disrupting financial support for other far-right news media in—or impacting—their home countries. Based on interviews with leaders of eight Sleeping Giants chapters, as well as the related UK-based Stop Funding Hate campaign, this study examines the Sleeping Giants campaign with respect to its continuity with media activism of previous eras, while also seeking to understand its potential as one of the first high-profile activist campaigns to grapple with the impacts of programmatic advertising on the news ecosystem. In particular, we consider how the campaign’s interventions speak to the larger debate around the normative relationship between advertising and the performance of the news ecosystem.