Despite providing firms with tremendous business opportunities and benefits, social media exposes firms committing wrongdoings to threats of social media firestorms. Firefighting social media firestorms is one of the biggest challenges facing firms. Social media users gang up and leave messages to criticize and vent their anger on firms’ wrongdoings. These messages are highly persuasive, swaying other social media users into supporting the firestorms. Spreading like a wildfire, social media firestorms are difficult to control and the impacts on firms are far-reaching and deteriorating. To derive insights into tackling such issues, we draw on the rhetorical appeals in persuasion and the literature of moral psychology to develop a research model that explains the mechanism through which individuals participate in social media firestorms. We examine the effects of rhetorical appeals (i.e., ethos, pathos, and logos appeals) and moral judgement on one's intention to participate in such firestorms. The research model will be tested with social media users using an online experiment. This study is expected to contribute to the growing body of knowledge of social media firestorms and provide managerial implications for tackling such issues.