I think you're looking for consistency that the legal system just doesn't provide. The music industry is more organised and litigious than the software industry and that gives them power that you and I don't have. If you called it "Napster 2.0" specifically you'd probably be prevented from shipping by a preliminary injunction. Is that fair or consistent? No. But it's the world we live in. Programmers want laws to be irrefutable and executable logic but they just aren't.