I feel the need to point something out, though others might have already:
When you purchase a game you are not purchasing the data on a single CD but a licence to access the data on it. For this reason you don't own that data, not in the slightest, which is why it is a breach of contract if you modify or even unencrypted much of this data. There is a small fee for the media the data is printed on of course, distribution companies need profit too, but that is about it for buying a copy. Interestingly this fee is on all media you purchase, even blank CDs have a fee to pay off distribution companies for the cost of anyone copying data onto blanks instead of buying it from them. Bet you didn't know that, it is something they set it up in VHS era and no one ever repealed.
The upside of this is, because you are purchasing a licence to use that data, that it doesn't matter what that data is printed on. Hell it can be printed on punch cards, if you want to have a ware house filled with the damn things, and it won't matter the slightest as none of that is 'illegal'. As long as you can assure no one is accessing the data then no breach of contract, your licence is still valid and all that stuff.
This is also why I always put 'illegal' in quotation because it isn't a crime persay but a civil matter, a breach of contract that the companies have to sue you for in civil courts. Before someone cries out that I am wrong I will point out that mass sale is a crime but not for reasons most people think of. It is considered defrauding customers given that the licences they are purchasing are fake, even if it is clear they are fake it still is fraud to sell them to the 'unsuspecting' public.
As there is many reasons for making a back up copy of any data it only makes sense that the media doesn't matter, only the data and your right to access it.