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New anti-piracy proposals being debated in Congress are either a trap to ensnare popular websites like Facebook and YouTube, or a needed legal tool to stop rogue operators overseas from stomping all over copyrights.

To hear critics tell it, a pair of bills on Capitol Hill would punish Internet giants and start-ups alike for hosting everything from web videos to remote "cloud" data in the name of policing copyright infringement.

But the lawmakers pushing the bills say they're trying to target the "worst of the worst" sites dedicated to profiting off pirated material, not mainstream sites. After a similar piece of legislation failed to clear Congress last year, Sen. Patrick Leahy, D-Vt., offered a cleaned-up version of the bill this past May that addressed some of the concerns of technology groups by more carefully defining what type of sites could be targeted.

House Judiciary Committee Chairman Lamar Smith, R-Texas, introduced a related bill late last month.

The two bills, generally speaking, aim to give the Justice Department new powers to go after supposedly rogue websites dedicated to infringing activity or counterfeit goods, and copyright holders more limited power to do the same.

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It was Smith's bill that really set off alarm bells, though, as technology and free-speech groups claimed it would drastically expand the scope.

David Sohn, senior policy counsel with the Center for Democracy and Technology, said any website -- from Facebook to Twitter to YouTube -- that features user-generated content could be targeted under the bill.

"It sweeps much more broadly," he said.

Judiciary Committee aides vehemently reject this claim.

But Sohn said the House version is too broadly worded. One section describes culpable sites as those "committing or facilitating" violations. Another section describes culpable operators as those that "avoid confirming a high probability" of infringement violations.

Sohn said a service like DropBox or YouTube could fall under that category. "If you operate at any scale, you know that there's going to be probably some copyright violations there," he said, adding that the bill could punish companies for not actively policing their users. He said smaller, start-up sites without the legal infrastructure to defend themselves against claims could have a particularly tough time.

"This creates a potential exposure for any entity that is providing a platform on which users can post or store content," Sohn said. While Leahy's bill focuses mainly on foreign sites, Sohn said some American companies use foreign domain names, and that Smith's bill has provisions that would cover foreign and U.S. sites.

Advocacy group Demand Progress also complained that Smith's bill could "undermine" major websites that rely on user-generated content. The group flagged one provision that would criminalize the streaming of some copyrighted content, and said the bill is "set to suffocate free speech and innovation and terrorize consumers and Internet users."

Supporters say the legislation would only target the most "egregious" offenders, and is designed to protect intellectual property rights -- and in turn protect businesses from losing money to pirated content.

A Judiciary Committee aide said the claims being made about the proposal are "completely false." The aide said the intent of the bill is to target rogue foreign sites, and then halt their illicit activity by pressing third parties to sever ties with them.

"It's not going after YouTube, it's not going after Facebook, it's not going after any of those types of sites," the aide told FoxNews.com.

Another aide stressed that anyone bringing a complaint against a site would have to go through the courts, and would not be given unilateral power to choke off a site. The aide said "legitimate sites" have nothing to fear, and that the violations would have to be "willful."

Businesses and trade associations, including the U.S. Chamber of Commerce, have called for tougher legislation from Congress.

U.S. Chamber CEO Thomas Donohue said in a statement that the sponsors of Smith's bill were "standing up to the mass theft of American intellectual property."

According to the Chamber, "rogue sites" draw 53 billion visits a year.

The National Consumers League also applauded members of Congress for working on the problem.

"Rogue websites harm consumers. Sometimes the harm is blatant, such as sites peddling counterfeit pharmaceuticals that can injure or even kill consumers. Other times the harms are subtler, as sites purporting to sell discount clothing, footwear, or other consumer goods pass off low-quality, counterfeit items as legitimate," the group said. "These sites also harm U.S. workers, whose creations -- be they manufactured goods or digital movies, music, software or games -- are stolen, and the revenues that should have been used to pay higher wages or create more jobs are instead diverted to enlarge the coffers of criminal enterprises."

Under current law, websites can be ordered to take down particular content that infringes on a copyright. But these bills would give the Justice Department the power to compel payment providers, ad services, search engines and service providers to cut ties with offending sites, while going after the operators themselves.

Leahy's bill has cleared the Senate Judiciary Committee, while Smith's was only introduced late last month. Leahy's bill has 35 co-sponsors; Smith's has 12.