For the record, like nearly everyone else who has thought about the importance of a freely operating Internet to the cultural, political, and economic vibrancy of the United States, I take a dim view of the Orwellian-named "Stop Online Piracy Act" being considered in Congressional hearings today.
For more of the reasons why opponents of the bill have declared today "American Censorship Day," go to the ACD site, or Fight for the Future, or Mozilla's site. And for a how-to of Internet censorship a la Chinoise, there is this Atlantic piece from three years ago, still basically true to the operations of the Great Firewall. In the NYT Rebecca MacKinnon makes the Great Firewall-SOPA connection.
The Vimeo clip below does a very clear and concise job of explaining the commercial, technical, and political issues at stake. Short description of the problem: in the name of blocking copyright-infringing piracy sites mainly outside the United States, the bill would make U.S.-based Internet companies legally liable for links to or publication of any pirated material. This would be technically cumbersome, economically and commercially dampening, and potentially politically repressive. The video tells you more.