CloneCD Query - Backing up for other people

Hi,
Am new to this backing up lark and have downloaded CloneCD trial to test it out, what I wanted to know was, is it possible to back up other peoples games for them, or do they have to own CloneCD as well, I only ask this cos a couple of the guides I’ve read about it talk about enabling the Hide CDR media in the tray bar, and obviously if they dont own it will their backups not work for them on their machines?

Thanks guys