“Public libraries are invisible in most debates about copyright as it affects mass consumption. Still, they are the institutions which have the longest experience of making copyright goods available fairly to people who have not paid directly for them; and in all the time libraries have been around, no one has come up with a better model. Libraries don’t abolish copyright, and in some ways are more scrupulous about it than most institutions. But they allow the price of copyright goods to be lowered to the point at which they become worthwhile both for individual buyers and for the makers.”