Thank you Bram! Setting owner as root and writing permission only to owner I got it locked as desired. Do you know if there is a way to set the proxy globally for all users? Otherwise, any new user I create, I'll have to set proxy and change the kioslaverc owner.
I want to have the proxy settings locked in a way any system user can not change it. This can be easily done in FFox, but I couldn't find the way to do so in konq/kfm. Where do konqueror save its proxy settings?