Unauthorized ops will show up if the current client is not logged to any db (shows assert 16554).

If the user is logged in to a db and tries to perform ops on another db which it is not authorized, no log will show up unless the verbosity is cranked up to at least level 1 (show assertion 16550).

The behavior is inconsistent and can be misleading especially for users who intend to use logUserIds=1.