Most people probably haven't paid much attention to the huge corporations waging war in Washington over legislation designed to crack down on online theft of movies, music and other content. But the conflict will hit consumers in the face today when Wikipedia and several other websites intend to go dark to protest the proposed changes.

Wikipedia founder Jimmy Wales announced Monday that the hugely popular online encyclopedia would be unavailable for 24 hours to protest the Stop Online Piracy Act and related legislation, which opponents say could lead to censorship or the complete shutdown of some websites.

Wikipedia plans to join Reddit, Boing Boing and hundreds of other sites in the so-called SOPA Strike, an attempt to publicize their complaints about proposals supported by the movie and music industries and other media companies.

"'Freedom is never voluntarily given by the oppressor, it must be demanded by the oppressed,' MLK. On Wednesday, Wikipedia demands," Wales said via Twitter on Monday, Martin Luther King Jr. Day.

In a statement announcing the shutdown of the English-language version of the site, Wales said the legislation would "harm the free and open Internet and bring about new tools for censorship of international websites inside the United States."

The Motion Picture Association of America and others driving the legislation said real progress had been made toward creating a law that would protect intellectual property. The advocates said misinformation is inflaming passions on the Web while doing nothing to solve the problem of piracy.

"It's part and parcel of a campaign to distract from the real issue here and to draw people away from trying to resolve what is a real problem, which is that foreigners continue to steal the hard work of Americans," said Michael O'Leary, the executive leading the MPAA's campaign for the bills. He called today's plan an example of the "gimmicks and distortion" that have been used in an attempt to block the legislation.

The protesting websites — which reportedly also will include Mozilla, WordPress and TwitPic — plan to act today despite a signal from President Barack Obama's administration last weekend that it wanted changes in the legislation.

"While we believe that online piracy by foreign websites is a serious problem that requires a serious legislative response, we will not support legislation that reduces freedom of expression, increases cybersecurity risk or undermines the dynamic, innovative global Internet," said a statement from three White House officials.

Internet operators — including giants Google Inc. and eBay Inc. — have opposed the legislation because, they said, it would let companies move to block websites.