When do citizens engage in vigilantism in response to misinformation, and what drives them to do so? How can the potentially disastrous effects of such messages be neutralized? Despite their dangerous consequences, little existing research—in South Asia or elsewhere—has explored the factors associated with vulnerability to such misinformation and subsequent participation in violent acts, nor examined ways to limit the impact of such messages. In this Meta-funded project, we expand our research on fake news and propose to investigate the link between misinformation and vigilantism through a unique two-country study in India and Pakistan.