A method for using the screen names of users are used to appropriately
tailor a service for the users. If the service is a restricted service,
then the screen name is used as the basis for deciding whether access
should be granted to ensure that access is granted to a limited set of
users. Alternatively, if the service is comprised of several component
sub-services, and some of those sub-services are restricted, then the
screen name is used as the basis for deciding whether access should be
granted to the relevant sub-service.