Glenn Greenwald, Salon:
...SOPA opponents were confused and even shocked when they learned that the very power they feared the most in that bill — the power of the U.S. Government to seize and shut down websites based solely on accusations, with no trial — is a power the U.S. Government already possesses and, obviously, is willing and able to exercise even against the world’s largest sites (they have this power thanks to the the 2008 PRO-IP Act pushed by the same industry servants in Congress behind SOPA as well as by forfeiture laws used to seize the property of accused-but-not-convicted drug dealers...
Julian Sanchez, Cato (possibly Koch-funded, sorry):
There are good reasons SOPA and PIPA attracted more attention [than PRO-IP]: Instead of “seizing” domains directly at the registry, they would have imposed blocking and filtering obligations on thousands of ISPs and search engines, creating a whole host of technological and security problems. There was also the private right of action, which seemed more susceptible to abuse by overzealous copyright owners who were able to find a friendly judge. But the central power of the government to shut down web domains is already there in PRO-IP, and has been used to seize hundreds of sites already — wrongfully in at least some cases.