hypothetical scenario question

[Marvin GodfatherofSoul Bellamy]

I'm just thinking back to my days as a high school computer lab admin. 
 My biggest problem was preventing the kids from screwing up the desktop 
environment.  I know it made me look like a grump complaining about new 
backgrounds, but it made it much easier to tell at a glance when a 
machine had been altered if all the desktops shared the same setups.  Is 
there any way block user modifications to the desktop with KDE?  I've 
never used GNOME.