Across cities in eastern Congo, youth groups are involved in urban policing, operating between state and non-state actors and formal and informal governance. While some are responsible for improving security in their neighbourhoods, others contribute to its deterioration. This briefing explores the role of these groups, considering for instance, how they may be co-opted or employed by state security actors, criminal organizations or politicians; how their organization and activities vary significantly across space and time; and how they act not just as security actors, but also shape the social order of their neighbourhood and city, rendering themselves socially and politically significant. As inherently ambiguous and fluid, the authors argue they should not be romanticized as necessarily more legitimate auxiliaries of, or alternatives to, state security forces, and caution about their inclusion in donor programming.