Citizen-gathered evidence (CGE) gathered by individuals organized in collectives have the potential to demonstrate environmental and social wrongdoings in court. We identify (collective) agency and resistance in how individuals and communities that have been exposed to socio-environmental stressors turn to gather CGE. We explore the modes through which people gather scientific data, produce CGE, alert authorities to environmental harm, and the methods by which data can be shared with communities, beginning with the case studies of civic environmental monitoring addressing coal ash pollution in North Carolina. We analyze the case studies through a theoretical lens built on (1) the theory of civic monitoring “as resistance;” (2) the argument that CGE can embody “collective intelligence;” and (3) the concept of “crowd science” through a decentralized yet coordinated network. In the first part of the article, we introduce the case studies. Then, we illustrate our theoretical frame as applied to the analysis of the cases. We discuss the cases and in particular the CGE at issue through the prism of the frame. We demonstrate how CGE can be valuable not only for civil society and civic organizations, but also for competent authorities. In our conclusion, we identify critical junctures of our case studies, such as that of “knowledge crowdsourcing” to demand justice that triggers the government to take action and the existence of a “coordinated” yet decentralized crowd to capture the full extension of the problem. Lastly, we outline the limitations of our study, a future research agenda, and still open questions.