The English version of the Wikipedia website will be shut down for 24 hours in protest at new laws being proposed in America to stop online piracy.
Wikipedia's founder, Jimmy Wales, told Newsnight he agrees with protecting copyrighted content but not with the way it is being done.
But Michael O'Leary of the Motion Picture Association of America said that Wikipedia's 24-hour blackout was a "cute gimmick".
For over a decade, we have spent millions of hours building the largest encyclopedia in human history. Right now, the U.S. Congress is considering legislation that could fatally damage the free and open Internet. For 24 hours, to raise awareness, we are blacking out Wikipedia.
Learn more at http://en.wikipedia.org/wiki/Main_Page