I've created a brand new usergroup today and the only thing I did different, is a custom banner for that specific group. I've noticed everytime I log with any of the users from that group, a small key icon appears near the username.
Another admin updated the avatars for tha specific group without telling me and while the avatar itself doesn't look anything like a key, the very small version does...thus the retarded confusion. I really thought it has something to do with permissions