The article analyzes the strategies and speech practices of protest mobilization agents in social networks. As a technology for mobilizing protesters, network mediatization of a local incident is considered. A theoretical model of the network protest mobilization is proposed, and partial dichotomous strategies of mobilization agents are formulated. The empirical material is based on the analysis of a specific local event that received protest potential in social networks and turned into a real confrontation between civic activists and local authorities. The study is interdisciplinary and is carried out at the intersection of the philological theory of speech acts, the theory of political discourse and the theory of mediatization. The institutional approach of the agenda setting theory is used, methods of mathematical processing of big data are applied. The purpose of the study is to identify speech strategies directly or indirectly explicated in the speech practices of protest discourse agents on social networks, using the example of a mediated conflict caused by the plan to build an Orthodox cathedral in Yekaterinburg in 2019. The authors have shown that mediatizing a local incident on social networks can act as a mechanism for mobilizing political protest, thus, the basic hypothesis of the study is confirmed.