“On January 18, 2012, in an unprecedented decision, the Wikipedia community has chosen to blackout the English version of Wikipedia for 24 hours, in protest against proposed legislation in the United States — the Stop Online Piracy Act (SOPA) in the U.S. House of Representatives, and PROTECTIP (PIPA) in the U.S. Senate. If passed, this legislation will harm the free and open Internet and bring about new tools for censorship of international websites inside the United States.”
Press releases/English Wikipedia to go dark – Wikimedia Foundation