Academics Helen Margetts and Peter John explain how social media are now inextricably intertwined with the political behaviour of ordinary citizens. Margetts and John visit the RSA to show large-scale data and experimentation that explore how such dynamics inject turbulence into politics, which is increasingly characterized by instability, unpredictability and often unsustainability. These patterns of mobilization bring us shocks and surprises (from Jeremy Corbyn to Donald Trump) which traditional political institutions struggle to accommodate, with profound implications for models of democracy.