...Many people opposed to the bill agree in principle with its aims: Illegal music piracy is, well, illegal, and should be stopped. Musicians, artists and content creators should be compensated for their work. But the laws critics do not believe that giving the federal government the right to shut down websites at will based upon a vague and arbitrary standard of evidence, even if no law-breaking has been proved, is a particularly good idea....
This is exactly what happens in every other form of publishing and distribution. Why would it be a "not particularly good idea" to apply it to the Internet as well? If the Internet pirates (Google, &c - you know - paupers every one) have their way, the musicians will die broke long before the issue is dealt with.
Bobby