This study investigates the case of Reddit API Controversy 2023 as an online movement that transpired exclusively within the Reddit platform involving participation of huge online communities and its users. In protest of Reddit’s paid API restriction, its users and moderators of various communities or subreddits began shutting them down, and spreading the information about the potential harms of such a restriction for website use. The exploratory research was done using methods of computational text analysis of 33,232 user comments and social network analysis of users’ action history data. The research reveals the dynamics of the movement, topics of user discussions, and network structure of the subreddits which were actively commenting. These characteristics were compared with characteristics obtained in studies of hybrid modern social movements like Black Lives Matter and MeToo. The findings contribute to advancing theoretical frameworks in Reddit and digital social movement studies, offering insights into the specificity of user interaction on Reddit, virtual mobilization dynamics and the role of online platforms in collective expression.