Mechanisms for enforcing permissions on stored data. Prior to storing the data, a data structure containing the data is accessed, and then modified to include a license that represents permission(s) for how the data should be used when the data structure is later accessed. The modified data structure is then stored, after perhaps some optional transformation. When the data structure is later accessed, the license is acquired from the data structure. The license is then used to determine whether or not to honor specific requests to use the data. This determination may be made based on license validation instructions executed from a removable media. Furthermore, the license may be the exclusive determining factor for the license validation instructions in determining whether or not to honor specific requests.