removing shut-down, log out, reboot,

["Sw@g" <sweetthdevil gmail com>]

Hi all,

I am an happy user of gnome shell - and by the way great work!!!

The issue I have is the following, my pc is used at night to run various 
important (report and admin task) task and most of them I am not there 
to control it.

So I would like to be able to run a script to disable all possibility 
for the night user to either log out, reboot, or shut down.

As a I am running multiple user on the same machine for obvious reason, 
it ( the solution will be a script of some sort ) will be a script 
running while certain user log on, so then they aren't able to log out, 
reboot or power off the unit between a certain time.

Many thanks for your time,

Looking forward for your reply,