their sales were down not because people were nefariously copying their albums, but because their product was crap.

Well, close. The sales were down because people were getting copies of their albums before they bought them, and then finding out that they were crap, before spending their hard-earned frog pelts on them. People have been buying crap forever, and then selling the CD's back a few months later. Now, you can try before you buy, which puts the heat on groups like Metallica to make music worth paying for.