The unusual protest was visible across the Internet in many forms on Wednesday, with dozens of commercial and non-profit websites either closing down for the day or urging visitors to oppose what had until recently been a relatively obscure and technical legislative proposal.

Internet companies aim to get U.S. lawmakers to back off of bills designed to shut down access to overseas websites that traffic in stolen content or counterfeit goods.

The effort has gained traction. The White House over the weekend warned that overly broad legislation could harm free speech, and on Wednesday, House Speaker John Boehner acknowledged there was a lack of consensus on the bills.

Several members of Congress said the legislation appeared stalled, with some reversing earlier support for the measures.

The legislation, known as SOPA in the U.S. House of Representatives and PIPA in the Senate, has been a major priority for entertainment companies, publishers, pharmaceutical companies and many industry groups, who say it is critical to curbing online piracy that costs them billions of dollars a year.

But Internet players argue the bills would undermine innovation and free speech rights and compromise the functioning of the Internet.

"Something this big - which looks to be the largest and most prolific online protest ever in the short history of the Internet - that's bound to get the attention of lawmakers across the board," said Jeffrey Silva, an analyst at Medley Global Advisors.

Wikipedia mounted a 24-hour protest starting at midnight by converting their English page to shadowy black background and warning readers that "the U.S. Congress is considering legislation that could fatally damage the free and open Internet."

It included a link to help Internet users contact their representatives.

Craigslist, the free Internet classifieds site, also went black in protest, while Google's home search page included a black bar slapped over its logo, and asked readers: "Tell Congress: Please don't censor the web!"

Smaller sites, such as Reddit.com and BoingBoing.net, were also dark, with BoingBoing noting that the proposed anti-piracy bills "would put us in legal jeopardy if we linked to a site anywhere online that had links to copyright infringement."

Bill Allison, editorial director at the Sunlight Foundation, a lobbying watchdog group, said the Internet companies' 24-hour boycott was an effective campaign.

"It's a way of engaging the public in something that had been a very much behind closed doors kind of business as usual in Washington thing. It's a way to get the public aware and alerted to it, and somewhat on their side," Allison said.

MOMENTUM COOLS

The bills were seemingly on track for approval by Congress, but sentiment has shifted in recent weeks and an implicit veto threat from the White House has cast doubt on whether legislation will pass.

Republican Representative Tom Price, head of the House Republican Policy Committee, said in a hallway interview, "I don't think it is going anywhere."

"There is real confusion about it, number one, but number two, there are real concerns about whether or not it would it would shutdown the ability of entrepreneurs, new businesses and the like to utilize the Internet for their purposes," Price said.

When asked about the anti-piracy legislation at a news conference on Wednesday, Boehner said lawmakers will continue to try to find support for it, but that it's not there now.

"It's pretty clear to many of us that there is a lack of consensus at this point," Boehner said.

STAYING ON THE SIDELINES

Big tech names including Facebook and Twitter declined to participate in a boycott despite their opposition to the legislation.

The companies were not prepared to sacrifice a day's worth of revenue and risk the ire of users for a protest whose impact on lawmakers would be hard to gauge.

Google's solution allows the search engine giant to keep revenue attached to its searches, while still highlighting the issue.

The protest drew some criticism ahead of its launch.

"This publicity stunt does a disservice to its users by promoting fear instead of facts," Lamar Smith, Republican chairman of the House Judiciary Committee and a sponsor of SOPA, said in a statement on Tuesday. "Perhaps during the blackout, Internet users can look elsewhere for an accurate definition of online piracy."

Former Senator Chris Dodd, who now chairs the Motion Picture Association of America, labeled the blackout a "gimmick" and called for its supporters to "stop the hyperbole and PR stunts and engage in meaningful efforts to combat piracy."

(Reporting by Sarah McBride in San Francisco and Jasmin Melvin in Washington D.C.; Additional reporting by Diane Bartz and Thomas Ferraro; Editing by Maureen Bavdek and Tim Dobbyn)

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