Abstract: Contributions in this thematic issue focus explicitly on citizens and their online engagement with European politics. For social media research in the European Union, citizens remain an understudied actor type in comparison with political elites or news organizations. The reason, we argue, is four key challenges facing social media research in the European Union: legal, ethical, technical, and cultural. To introduce this thematic issue, we outline these four challenges and illustrate how they relate to each contribution. Given that these challenges are unlikely to dissipate, we stress the need for open dialogue about them. A key part of that involves contextualizing research findings within the constraints in which they are produced. Despite these challenges, the contributions showcase that a theoretical and empirical focus on citizens’ social media activity can illuminate key insights into vitally important topics for contemporary Europe. These include civic participation, institutional communication, media consumption, gender inequality, and populism.
Keywords: computational methods; European Union; Facebook; gender; news engagement; populism; social media; Twitter