Shouldn’t xscreensaver disable Ctrl-Alt-Backspace while the screen is locked?
Yes, it should. Unfortunately, that’s not possible with current versions of XFree86 or XOrg. It’s as if the developers of X11 and the Linux kernel want to make it as hard as possible for you to lock your screen.
A lot ways to disable the screensaver.
We might have to reconsider SysRq (Magic SysRq key) as per:
Backdoor #3: Alt-SysRq-F .
This is the Linux kernel “OOM-killer” keystroke. It shoots down random long-running programs of its choosing, and so might might target and kill xscreensaver, and there’s no way for xscreensaver to protect itself from that. You can disable it globally with: sudo ‘echo 176 > /proc/sys/kernel/sysrq’