You need to change the [Access Mode] for the service you wish allow or restrict for users. You do this by going to the [Any Service, General] tab and clicking on the [Access Mode] button. Once this opens you simply need to change it from the default [All Accounts] to [Selected Accounts Only, Selected Domains Only, Etc.]. Once this is set you can then go to each user/domains [Options] tab and uncheck the box for that service to remove it for that account or domain.