I have a hunch this question is going to have an answer that was staring me right in the face, but I can't seem to find it.
When I mount a CD (from the command line) and am running a GUI, nautilus will automatically open a window and attempt to display the contents of the CD. If the user running the GUI doesn't have read permissions on the mount point, it will still open a window and just not display the contents of the CD.
Needless to say, this is annoying. How do I stop it (without uninstalling nautilus)?