Scholars have long found profound normative and structural differences between the privacy movements of Europe and the United States, alongside incompatible regimes of regulation. After 9/11, both Europe and the U.S. adopted increasingly intrusive digital security measures, which impinged on the privacy of commercial and personal data. Both the overlap in privacy regimes and the securitization of the two regimes were uncovered by Edward Snowden’s revelations in 2013. The eventual result was the passage of a European privacy protection regulation, the General Data Protection Regulation, in 2016 and greater transnational diffusion and transnational cooperation among European and American privacy activists. But has this convergence produced a transnational movement for privacy? Studying three mechanisms of transnational mobilization—externalization, diffusion, and collective transnationalism—this article employs a political opportunity framework to understand how international events have increased the inclination and the capacity of nationally and regionally based privacy groups to come together in contentious collective action.