Wikipedia will shut down for 24 hours later this week in protest at draft anti-online piracy legislation before the US Congress, founder Jimmy Wales said on Twitter.
"Student warning! Do your homework early. Wikipedia protesting bad law on Wednesday!" Wales said on the microblogging site.
"'Freedom is never voluntarily given by the oppressor; it must be demanded by the oppressed.' MLK - on Wednesday, Wikipedia demands," Wales said, citing slain US civil rights leader Martin Luther King.
The Stop Online Piracy Act (SOPA) is currently before the House of Representatives, while the Protect IP Act is the version before the Senate.
Media tycoon Rupert Murdoch used his new Twitter account to slam US President Barack Obama for opposing parts of the bill, as well as accusing Google of helping pirates.
Google has brushed off Murdoch's criticism.
“Last year we took down 5 million infringing Web pages from our search results and invested more than $60 million in the fight against bad ads. ... We believe that there are smart, targeted ways to shut down foreign rogue websites without asking U.S. companies to censor the Internet,” the National Post quoted a spokesperson as saying.
The draft legislation has won the backing of Hollywood, the music industry, the Business Software Alliance, the National Association of Manufacturers and the US Chamber of Commerce.
But last month, the founders of Google, Twitter, Wikipedia, Yahoo! and other Internet giants expressed concern over the two drafts, saying in a open letter that they would "give the US government the power to censor the Web using techniques similar to those used by China, Malaysia and Iran."
"We urge Congress to think hard before changing the regulation that underpins the Internet," they said. "Let's not deny the next generation of entrepreneurs and founders the same opportunities that we all had."
Wales said Wikipedia would go dark for a full 24 hours in English, saying: "Final details under consideration but consensus seems to be for 'full' rather than 'soft' blackout!"
"This is going to be wow. I hope Wikipedia will melt phone systems in Washington on Wednesday. Tell everyone you know!" he said.
Volunteer-staffed Wikipedia turned 11 years old on January 15th and boasts being the largest encyclopedia in history with more than 20 million articles in 282 languages.
