I'm not sure that would apply here: in that case, you're talking about the right to make a backup copy of an item you've properly licensed, and then retain it o

I'm not sure that would apply here: in that case, you're talking about the right to make a backup copy of an item you've properly licensed, and then retain it only to use under the same terms as that original license. In this case, you're taking content that you haven't paid for, and violating the terms it's distributed under by disabling some portions so you can consume it without paying. I'd argue that's closer to disabling macrovision on a VHS tape so you can make a backup copy of a rental tape to keep for yourself, and I'm pretty sure that's verboten.