Mozilla writes on its web site: "The Greenpeace International website has gone dark today in protest of the U.S. Stop Online Piracy Act (SOPA) and Protect-IP Act (PIPA). The U.S. Congress is about to censor the Internet. If SOPA/PIPA become law, sites like Greenpeace.org could go dark simply because one of our corporate targets files a claim that its intellectual property rights have been violated. No proof required, no court hearing. Don't let corporate interests censor the internet."