1. A data processing apparatus including means for applying access controls to hierarchically organized data processing system resources, the means for applying access controls including: means for associating a scope of applicability with an access control for a first resource; and means for controlling the performance of an operation in accordance with the access control, wherein the means for controlling is responsive to a first scope of applicability associated with an access control to limit access control inheritability to less than all descendants of the first resource in the hierarchy.