If the idea of the government using technical measures to crack down on copyvio bothers you, Vixie's DNS RPZ mechanism should bother you even more; after all, the government is simply going to find other ways to shut down music sharing services, but RPZ seeks to standardize a method for any company to build blacklists for any reason.
http://www.circleid.com/posts/20100728_taking_back_the_dns/