<control><alt>backspace

[eddie]

<rant>
Never in all the years in computing have I seen a real issue with this key combination. It is called paying attention to what you are doing. I think this is a just fluff for wanting ubuntu to be locked down. I feel like I just lost some of my FREEdom by using linux. The key combination should be left on and up to the local admin to disable it. There has been many a time when I had this that or the other running in the background and rebooting the machine would cost me those jobs. The <control><alt>backspace was the best way to fix an x issue without losing what I am doing. It is also one of the features that drew me to linux. Obviously who ever thought of this idea has never done any real computing or does not understand the concept of avoiding downtime. Also rebooting may be fast, but it does add extra wear to a computing system. Who ever thought of this must be a expletive deleted mswindows programmer. Besides, dontzap is not installed by default as it should be (at least not when you do an upgrade).
</rant>

http://www.ubuntu.com about 9.04:
Ctrl-Alt-Backspace is now disabled, to reduce issues experienced by users who accidentally trigger the key combo. Users who do want this function can enable it in their xorg.conf, or via the command dontzap --disable (sudo apt-get install dontzap; dontzap -d).

[Colin]

It seems this is already done on Fedora too:

Some people are already aware that both Ubuntu and Fedora disable Ctrl-Alt-Bksp shortcut. There are hot discussions around that decision. Now, xkeyboard-config is a part of the battlefield. See this bug. At least, when that change is committed, users will be able to enable this shortcut back easily (for example, using gnome-keyboard-properties), by using proper XkbOption. But the default behavior would be as it is now in Ubuntu and Fedora - i.e. without that deadly feature.

from Sergey Udaltsov: To Zap or not to Zap.

Bugzilla – Bug 21274 -Make Terminate_Server on ctrl+alt+bksp an option