Functionality is described herein for receiving events which characterize features in an environment, and for identifying at least one policy based on the events. The functionality consults a certificate, associated with the policy, to determine whether the policy is valid. If valid, the functionality uses the policy to govern the behavior of at least one application, such as by controlling the application's consumption of events. A trusted passport authority may be employed to generate the certificates. Each certificate may: (1) identify that it originated from the trusted passport authority; (2) contain context information which describes a context in which the policy is intended to be applied within an environment; and/or (3) contain machine-readable content that, when executed, carries out at least one aspect of the policy.