This has nothing to do with how you access it, the Library of Congress, or anything else you mentioned.
Put yourself in the position of the the owner of the content for just a second. You have entered into a contract with Apple to sell your copyrighted content. You want assurances from Apple they will protect your content from being illegally distributed. The content owner knows Apple has iBooks locked down on a stock iPhone but they are not sure about jb devices. So they ask Apple, "Clearly you are aware there are jb devices out there. What are you doing to fulfill our contract and protect our content on jb devices?" What's Apple supposed to say, "Nothing."?
The position of the copyright owner is immaterial. Jailbreaking an i-device is legal. Apple may be appealing that ruling, but to my knowledge there has been no stay given on that ruling by any court. Therefore, my right to play my purchased material on my devices is being illegally prevented. Apple can say whatever it wants re its ability to protect content, the device I own is lawfully mine to do with as I wish. Unless it can be proven that I am illegally distributing copyrighted material, Apple needs to get out of the way of my using my device and my content as I see fit. I am not the lawbreaker here. Apple is. (And I own Apple stock.)