Images are central to social media communication. Billions of images are shared across different social media platforms every day: photos, cartoons, GIFs and short video clips are exchanged by users, facilitating or framing discourse on participatory sites such as Twitter, Facebook and Instagram. Many of these images depict events of extreme violence, which circulate uninhibited by the conventional constraints associated with traditional news media censorship. A question arises here as to how such images mobilize public and policy-making responses to atrocities. This article examines the political dynamics of violent social media images. I argue that the particular qualities of social media can play an important role in how the digital visibility of horrific violence influences policy-making as a response to such atrocities. There is an important connection between the properties of social media platforms that allow user images to reach a global audience in real time and the emotional responses that this level of circulation generates. In turn, the pressure created by events made globally visible through the circulation of violent images and the audience responses to those images puts governments in a position where they are forced to act, which has significant implications for policy-making.