He uses computational methods and big data to study protest dynamics, with a particular interest in how social networks affect individuals’ decision to protest. Early work argues that mobilization comes from action occurring on the periphery of countries’ social networks, and subsequent work has measured conflict dynamics in Ukraine and the social media use of activists. New work explores how to measure the kinds of people who protest based on images shared on social media; the effect of internet outages on political beliefs; and simulations to study the interaction between protest and repression.