Rixasha: I for one would rather lose my operating system which I can always install again, than my own files which are potentially irreplaceable..
Mmmm well you'd either lose your files, or you'd lose both. Unix/Linux systems will most likely let you delete every file on the computer, then when it goes to the next line of the script barf because the script is gone (
maybe if it's going line by line), then barf again when it tries to run anything that's not an internal command, then fall back to the last shell that's still in memory... probably...
A simple solution to the problem is to make a unique user account just for games. It may seem silly, but at the same time it's exactly what most of the OS uses internally for it's operations, as you'll find usernames in Unix/Linux systems called
ftp, admins, printer, backup and other assortment of names, which gives far more precise control over what files they can run or access period limiting their level of exposure in a worst case scenario...
Actually
glancing at the list,
games already exists... meaning probably that Valve should think better to make use of that account rather than using the user's account if possible...