@kev-m I figured this out. I was looking at the Global permissions and not the category specific permissions. To change the category there is a dropdown menu on the upper right hand side of the Manage>Privileges page. Then I select the category and remove the guest permissions.
Thanks a lot for your help guys and sorry for the false alarm, maybe the plugin in Github should have this warning. I know that is a dumb mistake and most of web developers may be aware of it but just in case.