The digital outcry: What incites participation behavior in an online firestorm?

Brands, celebrities, or politicians are increasingly facing enormous online outrages in response to moral misconducts. These online firestorms are characterized by high message volume, indignant tonality, and negative opinion climate. Based on the concept of moral panics, this article analyzes why people join online firestorms. We argue that participation behavior is driven by a moral compass and a desire for social recognition. Results of an experiment and a content analysis of user comments show that a higher number of participants decreases users' willingness to participate but fosters compliance with the prevalent opinion and tonality of the comments. We also observe that a higher moral arousal of the issue increases perceived similarity with previous participants, which in turn affects whether and how people participate. In total, our results indicate the importance of social context for participation behavior in an online firestorm.