A device and method for placing the device in a locked state having an associated set of permitted tasks so as to permit the device owner to share the device with others but maintain security over aspects of the device. A task change request is evaluated to determine whether the requested task is permitted and, if so, the requested task is allowed; if not, then an authorization process is invoked to prompt the user to input authorization data. Upon verification of the authorization data, the device may be unlocked and the requested change implemented. The permitted tasks may designate specific applications, specific operations or functions within applications or at the operating system level, one or more currently open windows, and other levels of granularity.