When wronged customers feel powerless they could bring publicly their fight against offending firms. Doing so could help to put the perpetrator firms under pressure and urge them to restore fairness. While some consumers could express their commitment to wronged consumers, others may disagree and disapprove their fight. This paper investigates consumers' motivations and roles in supporting and rooting against powerless customers‐ referred here as underdogs. Using a netnography approach to analyze online participants' postings, we identified two types of roles: supportive and unsupportive roles. The former consist of five consumers' roles that are endorsed when rooting for underdogs, namely the Admirer, the Rebel, the Learner, the Opportunist, and the Lawyer. The latter consists of four roles adopted by opponent consumers when rooting against underdogs, namely the Sarcastic, the Elitist, the Conformist, and the Schadenfreudist. Understanding consumers' roles and motivations in rooting for the underdogs, is helpful for firms in managing their defensive marketing efforts and reduce the anti‐corporate attitudes. Likewise, knowing what motivates consumers to root against an underdog may help in capitalizing on supportive attitudes and to reinforce the commitment toward the firm. This article is protected by copyright. All rights reserved.