Come to think of it, this is the real work rivaled of an API breaking change. It seems entirely reasonable to that we should have regulation that prohibits this kind of change after you've already purchased the product. But then again, in a sane system, you should either need to sign the user agreement for anything at purchase time or be allowed to return a device whenever you encounter a the (new) user agreement. Currently you might buy something that you cannot return and only then at the user agreement. The user aren't should be seen as pay of the purchase contract and the purchase shouldn't be valid without it being signed.