iTunes contains code that must be kept secret, i.e. encryption of audio streams to Airport Express, embedding user-info in mp4 files bought from the iTunes Stor

iTunes contains code that must be kept secret, i.e. encryption of audio streams to Airport Express, embedding user-info in mp4 files bought from the iTunes Store, communication and authentication of connected iPods/iPhones. So a fully open source iTunes for Linux would only be half-working: no updates of iPods, no buying from iTunes Store, etc.