ABSTRACTTerritorial infringement occurs when two consumers signal psychological ownership of the same object, such as a product or brand. We suggest that within virtual brand communities characterized by the community's collective ownership of the brand, signaling individual psychological ownership of the brand will be perceived as an infringement on the territory of the community as a whole. Combined with the increased visibility and permanence of territorial signals in virtual contexts, this will result in negative consequences for observers of the territorial interaction similar to those found for direct recipients of territorial behavior. Four experiments conducted across three different brand communities and social media platforms find that observers of territorial interactions experience vicarious territorial infringement that is perceived as a threat to their social identity as brand community members. These perceptions are diminished when the observer identifies with the infringing consumer as an individual, suggesting that they are linked to the shared social identity. We further find that vicarious territorial infringement perceptions have negative downstream effects on observers' affective and behavioral brand community engagement. Collectively, this suggests that territorial behavior has the potential to negatively impact multiple consumers within virtual brand communities.