Indeed, I completely forgot about the sudo/admin groups. Indeed "admin" has been the one introduced by Ubuntu since the very beginning; later "sudo" was introduced by Debian, and Ubuntu moved to it. So "admin" can safely be dropped once all sudo users got moved into "sudo".
** Changed in: policykit-1 (Ubuntu) Status: Incomplete => Triaged -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1451815 Title: lists users multiple time when requiring user authentication To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/policykit-1/+bug/1451815/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs