Ctrl-Alt-Bksp to exit a bad X session

In X Window System in fvwm, Motif, CDE, etc...you're able to exit out of a corrupt, hung, disk thrashing session just by pressing the key sequence:

Ctrl-Alt-Bksp

This is a very cool feature and saves one from having to do a complete reboot. Using this key combo. takes you back to the GDM login scrreen.

To add this feature, use the Gnome Tweak Tool and in the Typing tab, select the option Key Sequence to Kill the X Server, like so:

DONE.