According to https://confluence.atlassian.com/display/CONF40/Site+Administrators+and+their+Permissions there are three levels of admin access: super user, system administrator, and confluence administrator. The intriguing part of this for us is that only super users have access to all content.
This contradicts my experience. As far as I've been able to tell, people in at least the sytem admin group (and maybe people in the confluence admin group) as set on the View Gobal Permissions page can see all content. That page has no assignable admin permissions other than system admin and confluence admin, and I don't see anything that would assign super user access.
So, is this true? How can I assign super user status or more to the point, how can I remove super user access from system administrators and confluence administators?