keeveek: Polish law says nothing about ownership. You may also create a backup copy of a software you lease. I think it's applicable to digital distribution. But there are no doctrine opinions about it, many of them are just simply out of date. Polish supreme court is silent in this case.
Polish law says also, when license agreement forbids you to create a copy, these provisions are void.
But when you lease a software, you have to destroy the copy, when your leasing contract expires.
That would be a fun one to see in court. I assume, were it ever to be raised, the argument someone like valve would use would be that your contract expired when you broke the contract, which you did by backing up the software. It could then be argued in defence that the terms of the contract contradict your right to back the software up.
Who knows where that one would end up, probably with the more expensive lawyers winning. We don't have any such laws in the UK, so we're valve's biatches the second we pay them the money. At least its clear :).