Controlling data usage in a crisis scenario is a particularly acute issue due to the sensitive nature of the data being distributed. Typical access control mechanisms rely on a centralised architecture where access policies are stored and evaluated. However, such architecture is not practical in a crisis scenario due to the absence or the impossibility of using a wide-area communication infrastructure. In this paper, we introduce xDUCON a framework for enforcing usage control policies that relies on the Shared Data Space (SDS) abstraction for the coordination of policy evaluation and enforcement. Policies are represented as tuples to facilitate their propagation across the available infrastructure.