I agree that shoplifting isn't the right term. My point is that online copyright infringement is analogous to shoplifting in its impact. That is, not negligible, and something we wish would go away, and might want to put in some safeguards against, but not something so earthshatteringly destructive that we need new laws, including draconian new laws that require third parties to become enforcers.
BTW, someone sent in a GREAT link on the right term for what the music industry likes to call piracy. It's simple, and legally accurate: "copyright infringement." There's a great summary by Supreme Court justice Harry Blackmun at http://philip.greenspun.com/dldf/dismiss-order.html in which Blackmun makes clear why copyright infringement is not the same as theft, for much the same reason you outline in your posting.