Concerns that legal websites will be targeted is overblown, said an aide for the House Judiciary Committee. "The provisions of this bill only target websites dedicated to illegal activity," she said. "Sites that host user content -- like YouTube, Facebook and Twitter -- have nothing to be concerned about under this bill."

Legislation is needed to protect U.S. residents, sponsors argued.

"Intellectual property is one of America's chief job creators and competitive advantages in the global marketplace, yet American inventors, authors, and entrepreneurs have been forced to stand by and watch as their works are stolen by foreign infringers beyond the reach of current U.S. laws," Representative Bob Goodlatte, a Virginia Republican, said in a statement. "The bill will also protect consumers from dangerous counterfeit products, such as fake drugs, automobile parts and infant formula."

Several groups, including the U.S. Chamber of Commerce, the Motion Picture Association of America and Comcast, applauded the lawmakers for sponsoring the legislation.

"Our broadband customers will continue to access and enjoy all legal content," Kyle McSlarrow, president of Comcast/NBCUniversal, said in a statement. "The Stop Online Piracy Act is narrowly targeted to only illegal streaming activities or rogue websites found by a court to be engaged in trademark counterfeiting or illegally reproducing or distributing material protected by copyright. Thus, this legislation, if enacted, would protect the Internet as an engine of innovation and economic growth, rather than as an environment that allows digital theft and counterfeiting to thrive."