Some of Washington’s most powerful lobby groups ramped up their fight today over the Stop Online Piracy Act, which was just introduced in the U.S. House of Representatives. The Independent Film & Television Alliance echoed points that MPAA chief Chris Dodd made in a speech today — that the bill empowering the government to block overseas websites that traffic in copyrighted content would protect jobs. It’s needed to stop “drastic damage to the legitimate marketplace … measured both in films that cannot be produced and in lost returns on investment in films that have been,” IFTA CEO Jean Prewitt said.  National Association of Theatre Owners CEO John Fithian adds that the legislation “is an important step to protect the jobs of 160,000 movie theater employees and sustain one of the vital engines of the nation’s economic growth.” The plan also was supported by a collection of unions including the American Federation of Musicians, American Federation of Television and Radio Artists, Directors Guild of America, International Alliance of Theatrical Stage Employees, International Brotherhood of Teamsters, and Screen Actors Guild. If the bill doesn’t become law, they said in a joint statement, then “rogue sites will continue to siphon away wages and benefits from members of the creative community, greatly compromising our industry’s ability to foster creativity, provide opportunities, and ensure good jobs.”

But Consumer Electronics Association CEO Gary Shapiro warned that if Congress passes the bill — also known as the Protect IP Act — then “the notoriously litigious content industry could simply accuse a site that it is selling a product that could ‘enable or facilitate’ a copyright infringement, thereby allowing accusations to shut down sites vital to the Internet economy.” He says that “could lead to mass shutdowns of websites and Internet-enabled services.” The group plans to bring several Internet venture capitalists to Washington tomorrow to make that case.

While content owners and tech companies slug things out, cable companies straddled the fence. National Cable and Telecommunications Association CEO Michael Powell said the group favors “new, reasonable tools that will protect copyrighted goods while balancing the obligations of organizations that conduct business on the Internet.” Cable companies, he added, “will continue to explore further steps to thwart digital theft and we look forward to working with the House Judiciary committee on this important legislation.”