securing gnome logoff

[Tristan Wibberley]

Hi,

I've googled for this and checked the ubuntu lists, but I can't find the
answer I'm looking for.

I'd like to prevent users from using the options on the gnome logoff
menu from shutting down, rebooting or hibernating the system. Local
users will not have physical access to the power switch, cable, or mains
socket. Nor will the kernel have SysRQ enabled.

I've also got the problem that users logged in remotely via freenx get
the shutdown options when logging out, and they *especially* should not
be able to shut the machine down.

If anybody can advise how I can secure GNOME on Ubuntu, I'll be very
grateful.

--
Tristan Wibberley