Thanks for all your thoughts.
I managed to disable Tools -> Options -> Security -> Saved Passwords so nobody can look there for my saved passwords.
In order to explain my problem better, here's an example:
- I have admin rights on my PC. The other users don't.
- I have a basic CMS.
That's just an example.
So, what I would like to do is:
- disable window.alert in Firefox
Thanks for all your help guys.