James Losey and Sascha Meinrath in Slate:
The interconnected nature of the Internet fostered the growth of online communities such as Tumblr, Twitter, and Facebook. These sites host our humdrum daily interactions and serve as a public soapbox for our political voice. Both the PROTECT IP Act and SOPA would create a national firewall by censoring the domain names of websites accused of hosting infringing copyrighted materials. This legislation would enable law enforcement to take down the entire tumblr.com domain due to something posted on a single blog. Yes, an entire, largely innocent online community could be punished for the actions of a tiny minority.
If you think this scenario is unlikely, consider what happened to Mooo.com earlier this year. Back in February, the Department of Justice and Department of Homeland Security seized 10 domains during a child-porn crackdown called “Operation Protect Our Children.” Along with this group of offenders, 84,000 more entirely innocent sites were tagged with the following accusatory splash page: “Advertisement, distribution, transportation, receipt, and possession of child pornography constitute federal crimes that carry penalties for first time offenders of up to 30 years in federal prison, a $250,000 fine, forfeiture and restitution.” Their only crime was guilt by association: They were all using the Mooo.com domain.
SOPA would go even further, creating a system of private regulation to shut down websites that are accused of not doing enough to prevent infringement. Keep in mind that these shutdowns would happen before a site owner could defend himself in court—SOPA could punish sites without even establishing whether they are guilty of the charges brought against them.