The anti-piracy battle gripping Washington and the Internet pits two US West Coast power bases directly against each other: Hollywood is taking on Silicon Valley over the right to make money online.

Backing two controversial pieces of draft anti-piracy legislation, the Los Angeles-based entertainment industry is calling for non-US websites to be held to the same standards as US ones.

But a couple of hundred miles up the coast, the giants at Google and Facebook are resisting at all costs moves which they claim will stifle development of the Internet -- on which their own future, and income, depends.

On Friday, US congressional leaders put anti-online piracy legislation on hold following a wave of protests led by Google and Wikipedia denouncing the bills as a threat to Internet freedom.

Senate majority leader Harry Reid said he was delaying next week's vote on the Protect IP Act (PIPA) and House Judiciary Committee chairman Lamar Smith said he would "revisit" the House version, the Stop Online Piracy Act (SOPA).

In a joint statement Friday, the American Federation of Musicians, American Federation of Television and Radio Artists, Screen Actors Guild and other entertainment industry groups called on US lawmakers not to bow to pressure.

"We fought for this legislation because illegal Internet businesses that locate offshore expressly to elude US laws should not escape the very same rules of law that currently apply to illegal US websites," they said.

"They should not be allowed to reap in profits if they knowingly sell or distribute illicitly gained content and goods which they had no role in creating or financing to the American consumer," they added.

The draft legislation has won the backing of Hollywood, the music industry, entertainment giants like Rupert Murdoch's News Corp., angered at the enormous income lost from online streaming and downloads of their products.

But the bills have come under fire from online companies and digital rights groups for allegedly paving the way for US authorities to shut down websites accused of online piracy, including foreign sites, without due process.

"We want a world in which creators are properly compensated for their work, everybody is in favor of that," Corynne McSherry, lawyer for the Electronic Frontier Foundation (EFF), which promotes free speech online.

But "the right answer to that is not legislation, that's never going to happen in Washington DC, it has to happen via innovation, not legislation," she told AFP.

And she said: "Fighting the internet doesn't work. The answer is to embrace a new business model, that's the only thing that ever worked."

She cited the case of VCR technology, followed by DVDs, which were initially fiercely resisted by Hollywood, but in the end were accepted and turned into a huge new source of revenue.

The six-strong Hollywood grouping acknowledged that the question is complex.

"We recognize that we are currently part of a complex and important debate about the future, not just of the Internet but also of creativity, the American economy, free expression, and a civil society," its statement said Friday.

"We hope a new tone can be set that does not include website attacks, blacklists, blackouts, and lies. We believe an Internet that does not allow outright stealing has to be the Internet of the future or all the promises it holds will be unrealized."

On Wednesday, the English-language version of its online encyclopedia shut down for 24 hours to protest the legislation and hundreds of other sites joined in the protest.

On Thursday, US authorities shut down Megaupload.com, one of the world's largest file-sharing sites, and charged seven people in what they called one of "the largest criminal copyright cases ever brought by the United States."

The Motion Picture Association of America (MPAA) said last week that the US government has to act.

"On behalf of the 2.2 million Americans whose jobs depend on the film and television industries we look forward to the administration ... working with us to pass legislation that will offer real protection for American jobs," it said.

But EFF lawyer McSherry was not convinced, saying the entertainment industry needs "a new leadership that is more focus on innovation than saving yesterday's industry."