Mobilising the mob: The multifaceted role of social media in the January 6th US capitol attack

On January 6, 2021, a social media post by Donald Trump became a driver for the violent storming of the US Capitol. The attack fuelled discussions about social media’s role in political polarisation and extremism and raised questions about how platforms should be governed. Multiple social media platforms were used to mobilise activists for the Capitol attack. By drawing on findings from investigations and the January 6 congressional report, this paper examines how platform-specific design, features, and policies influenced their use in the mobilisation of January 6. Consensus mobilisation, the process of convincing people that action is necessary, primarily took place on platforms with open network structures and algorithmic filtering. In contrast, more private messaging apps and platforms with minimal moderation were used more for action mobilisation: the organisation and planning of the attack. These findings stress the importance of considering variations in the design of social media platforms to better understand political mobilisation.