In the default setup for irix boxes, xhost is set to global access whenever someone logs in on console (or invokes xdm). There may be some good reason for this default behavior, however it's often a nuissance in situations where one is around a lot of immature ppl just waiting to xdisplay '/usr/bin/X11/endsession -f' to your console. This system-wide default is set in config files residing in /var/X11/xdm You will probably need to edit the files: Xsession Xsession.dt Xsession-remote But to be sure, just grep for xhost, and change it to 'xhost -' where needed.