CD Backup Sites

I’ve recently become interested in making a cd backup site, before i turn this interest into production i would like to know how the sites do this legally (if they do it legally), i’ve read the disclaimer which has section 117 of the us copyright law etc…

Is the person already having a copy of the software enough to make it legal or is there something else invloved such as the cds being burned in another country which has less protection from software copyright.

Before i go any further into this i would like to know if its legal or ways to make it legal (A lot of you from gthe forum posts 've read seem to know a lot about law)