The White House responded to a petition urging a veto of the controversial Stop Online Piracy Act (SOPA) on Saturday and laid out its conditions for supporting anti-piracy legislation.

“While we believe that online piracy by foreign websites is a serious problem that requires a serious legislative response, we will not support legislation that reduces freedom of expression, increases cybersecurity risk, or undermines the dynamic, innovative global Internet,” the president’s advisers wrote.

House Judiciary Chairman Lamar Smith (R-Texas), SOPA’s sponsor, said his bill meets the White House’s requirements.

{mosads} “I welcome today’s announcement that the White House will support legislation to combat online piracy that protects free speech, the Internet and America’s intellectual property,” Smith said in a statement. “That’s precisely what the Stop Online Piracy Act does.”

SOPA and its Senate counterpart, the Protect IP Act, are designed to go after foreign websites that offer illegal copies of music, movies and TV shows with impunity. 

Movie studios, record labels and business groups say the bill is necessary to crack down on online copyright infringement, which is hurting businesses and destroying jobs.

But the measure has sparked a backlash from Internet freedom advocates and Web companies, including Google, Yahoo and Facebook, who say it would stifle innovation and censor free speech.  

The president’s advisers said they oppose a controversial provision that would require Internet service providers to block infringing websites through a process known as Domain Name System filtering.

“Proposed laws must not tamper with the technical architecture of the Internet through manipulation of the Domain Name System (DNS), a foundation of Internet security,” the White House wrote. “Our analysis of the DNS filtering provisions in some proposed legislation suggests that they pose a real risk to cybersecurity and yet leave contraband goods and services accessible online.”

In a major concession to the bill’s critics, Rep. Smith dropped the site-blocking provision from the legislation on Friday. Sen. Patrick Leahy (D-Vt.) said on Thursday he is open to changing the provision in the Senate version, the Protect IP Act.

Even without the provision allowing sites to be blocked, the bill would empower the Justice Department and copyright holders to demand that search engines delete links to sites “dedicated” to copyright infringement. Ad networks and payment processors would be prohibited from doing business with the sites.

Critics have questioned whether allowing private copyright holders to sue allegedly infringing websites would lead some companies to try to use litigation to kill off competitors. 

The White House warned against “unjustified litigation” but did not say the bill should be changed to only allow the government to go after infringing sites.

“Any provision covering Internet intermediaries such as online advertising networks, payment processors, or search engines must be transparent and designed to prevent overly broad private rights of action that could encourage unjustified litigation that could discourage startup businesses and innovative firms from growing,” the advisers wrote.

The White House emphasized that it is committed to giving law enforcement new tools to crackdown on copyright infringement.

“While we are strongly committed to the vigorous enforcement of intellectual property rights, existing tools are not strong enough to root out the worst online pirates beyond our borders,” the advisers wrote. “That is why the Administration calls on all sides to work together to pass sound legislation this year that provides prosecutors and rights holders new legal tools to combat online piracy originating beyond U.S. borders while staying true to the principles outlined above in this response. We should never let criminals hide behind a hollow embrace of legitimate American values.”

The White House urged the bill’s critics to work toward a compromise rather than oppose any new anti-piracy legislation.

“We should all be committed to working with all interested constituencies to develop new legal tools to protect global intellectual property rights without jeopardizing the openness of the Internet,” the statement said. “Our hope is that you will bring enthusiasm and know-how to this important challenge.”

The White House will invite the organizer of the petition and a random sample of the signers to participate in a conference call to discuss the issue with administration officials. The White House will also host an online event to get more input and answer questions.

House Oversight Chairman Darrell Issa (R-Calif.) said early Saturday morning that Majority Leader Eric Cantor (R-Va.) promised him the House will not vote on SOPA unless there is consensus on the bill.

But Smith promised to forge ahead on the legislation.

“I am committed to working with my colleagues in the House and Senate to send a bipartisan bill to the White House that protects free speech, the Internet and America’s intellectual property,” he said. “The Stop Online Piracy Act does just that and I look forward to working with the White House and the Senate towards its enactment this year.”