I guess that's a decent comparison, but I think you missed the point. Nobody is talking about "outlawing" mp3s or guitar playing. If you play your guitar in your room - that's fine. If you play with a bunch of friends, that's fine. If you play at a a gathering where you charge money and don't get permission from the artist, that is not necessarily fine. The same sorts of comparisons can be made with mp3s. Comparing different types and contexts of reproduction of intellectual property will get you somewhere, but only if they are on par with each other. So, taking the extreme on one end (getting compensated for another's property or distributing without compensating the artist) and comparing it with the other extreme (private use) doesn't make any sense. I think I might be talking to a wall though.