Seeing invisible users

Battle.net administrators have the ability to become invisible to normal users. However, until recently, this was flawed in that the server would expose the existence of an invisible user to regular users during certain operations. In particular, if one ignores or unignores a user, the server will re-send the state of all users that are ignored or unignored in the current channel. Before this bug was fixed, this list included any invisible users^3.3.