"Today, more than ever, fair use matters. In the courts, the doctrine is being creatively applied to guarantee fundamental fairness and balance. In other quarters, however, fair use is under threat. But the doctrine (like the vision of balanced copyright law that it represents) deserves to be defended and supported. Some of that support can come from the Congress of the United States, but much of it must derive from the various user communities that depend on the doctrine for the opportunity to make their cultural and economic contributions to our society."