How can policing communications deny terrorism its desired effect? British police have steadily mobilised social media to reach stakeholders. In May 2017, Greater Manchester Police communications were effective in mitigating communitarian divisions sought by the Islamic State and in inciting empathy, solidarity, feelings of security and police collaboration. Furthermore, by writing and describing the community, events and actors in ways that serve specific priorities, they were able to take advantage of these platforms. In this article, Jill S Russell and Pablo de Orellana deploy historical and discourse analysis approaches to analyse how police communications depicted the event, civic identity, the police force itself and the response.