Even if the downloads where encrypted, an all seeing observer could probably still detect what you download. See https://news.ycombinator.com/item?id=14070130 h

Even if the downloads where encrypted, an all seeing observer could probably still detect what you download. See https://news.ycombinator.com/item?id=14070130 https://news.ycombinator.com/item?id=14070130 as an example. I'm not sure how easy it would be to fingerprint the entire iTunes database and how unique download sizes would be. Might be an interesting research topic.