I'm working on a background service which needs to ask several users' iTunes settings (the users will opt-in via a helper application which they run from their login). Is there an easy way to read the preferences for another user, than the current one, using CFPreferences? The docs, for example for CFPreferencesCopyValue, explicitly state: 'Do not use arbitrary user and host names, instead pass the pre-defined domain qualifier constants.', when passing the 'userName' argument to the various functions.