It would help greatly when adding individual users to Visibility Groups if it were possible to select all members of a specific User Group from Control Panel>User Groups. Then individuals not required could be deleted. Otherwise users have to be added one by one, which would be a real pain, particularly in a school of any size! Also the ability to copy Visibility Groups would help: start with a group with all users, clone it, delete a few, then clone that one, and so on.