The present invention describes a method for superimposing prespecified locational, environmental, and contextual controls on user interactions, including interactions of mobile users, with computational resources. A system is described for electronically monitoring contextual information concerning users and machines, including state and locational information including proximity. Interaction policies, including user specified interaction policies, may be registered on an identifiable address path. Methods are described for detecting, selecting and controlling computercontrolled devices, based on the proximity of the device to the user, the current context of the user, the location of other nearby users and devices, and the current state of the devices. Temporary transfer of control, including exclusive control, of particular computers and computer controlled devices to individual users based on the context and environment in proximity to those computing devices is also described.