This article examines counterdisinformation policies to investigate how European countries are shaping the meaning and boundaries of social platforms’ accountability. We describe the cultural determinants of social platforms’ accountability through a content analysis technique that considered principles, actors, and instruments, resulting in four models of social platform accountability: accountability set by law, codecided accountability, regulated self-regulation, and pure self-regulation. Our results suggest that most of the 11 countries in this study maintain specific positions on the role of digital media in society. At the same time, some patterns of convergence were evident: the weakening of State control in favor of freedom of information; the enhancement of transparency in social platforms’ politics-related activities as a guiding principle to ensure public monitoring; and the standardization of a multistakeholder model of coregulation. The article also focuses on the technological dimension of social platform accountability, enabling us to recognize the degree to which different models rely on algorithms. It then problematizes the limitations and risks of social platforms’ accountability.