Increased use of social media comes at a societal price when influential actors, and the patterns of how and who they influence are hidden. When such patterns and structures are hidden, it prevents effective mitigation against their potentially harmful impact on trust and well-being in democratic societies. The project creates novel knowledge on this topic by studying social media as infrastructures for influence in national populations. The focus of the project on false information serves as a critical case for understanding influence, which becomes especially relevant in times of crisis and with social media's increasing role as an information source. The major contributions of the project are reconfiguring theoretical concepts for the analysis of social media influence, along with novel and innovative scalable methods and code to analyze influence and influential actors. In addition, the project contributes with empirical findings for a better understanding of information disorders by analyzing two main sources: 1) Facebook trace data from 28 European countries at a national scale, and 2) the YouTube watch-histories of 1,000 Danish citizens over 4.5 years. By analyzing the data in relation to citizens’ socio-demographic backgrounds, psychological profiles, measured and perceived influence, the project advances our understanding of social media influence.