This paper outlines a theoretical and methodological argument developing the concept of discursive opportunities in social movement studies and ways to operationalize it in a society increasingly dominated by social media discourse. High-impact studies on the wave of right-wing and racist violence in the 1990s and early 2000s established that mass media discourse on immigrants and on previous violent incidents had significant impact on the prevalence of extreme-right violence. This link was captured by Koopmans and Olzak’s (2004) notion of discursive opportunities, i.e., that the discursive environment of political action can enable or limit the impact of political messages and affect tactical choices of political activists. However, this was before the dominance of online social networks and social media, which radically came to change the media landscape, and hence how discursive opportunities for political violence are formed. In relation to the case of arson attacks on refugee housing facilities in Sweden 2015-2016, we discuss how discursive opportunities can be studied as a combination of mass media and social media discourses that contextualize these attacks, and identify the different mechanisms through which social media can impact on the incidence of violence.