The study monitors the evolution of perceptions and opinions of the terrorist group the Islamic State (ISIS) during its involvement in Syria and Iraq in 2013-2014. Data is drawn from a web-forum discussing current Islamic affairs that followed ISIS as early as September 2013. These data are used to answer the question of whether or not there are opinion leaders facilitating the discussion of violent extremist material. An interrupted time series and ordinary least squares regression are used to address the research question by determining the most impactful events on the thread, and determining the causal role of opinion leaders on the way users connect. Results indicate that the content and success of discussion are most impacted by the involvement of opinion leaders and media related to a specific ISIS event.