U.S. technology companies would face civil or criminal liability unless they take reasonable steps to protect global human rights under legislation a top lawmaker plans to propose.

At a hearing on Tuesday, Dick Durbin, chairman of the Senate Judiciary Subcommittee on human rights and the law, said there are questions over whether filtering software made by U.S. companies has been used to censor the Internet in several countries with repressive governments.

Durbin and some other lawmakers are pushing U.S. technology companies to join the Global Network Initiative (GNI), a voluntary code of conduct that requires companies to take reasonable measures to protect human rights.

So far Google Inc, Yahoo! Inc and Microsoft Corp have joined the standard-setting body. Some companies have balked at joining, citing membership fees, which range from $2,000 to $60,000 depending on the company's annual revenue.

Durbin provided few details of the legislation, which is in the early stages of drafting, but its goal is likely to make the GNI mandatory for U.S. tech companies.

This is an issue that will not go away, Durbin said.

The hearing comes after Google announced in January that it had faced a highly sophisticated and targeted attack in mid-December, allegedly from inside China, and declared that it was no longer willing to censor search results in the country as required by Beijing.

At the hearing, Google Vice President Nicole Wong said the world's top search engine is not prepared to say who is carrying out cyber attacks from China due to an ongoing investigation.

We do know such attacks are violations of China's own laws, and we would hope that the Chinese authorities will work with U.S. officials to investigate this matter, Wong said in prepared testimony.

She did not say when Google would make a final decision on its China business plans.

Google, which competes with Baidu Inc in China, said its revenue from China is small but said its fourth quarter of 2009 was the most successful quarter ever in China.

In January, U.S. Secretary of State Hillary Clinton unveiled an initiative to promote Internet freedom worldwide that includes grants to help citizens living under repressive regimes to access an unfettered Internet.

Assistant Secretary of State Michael Posner told lawmakers on Tuesday that since 2008, the department has implemented $15 million in programing to support online freedom and another $5 million in funds will be decided in the next several months.

In our latest request for proposals, we focused on access to information on mobile devices and cyber-security for (nongovernmental organizations) and digital activists, which we have identified as emerging trends, Posner said.

He said the State Department will convene a meeting Thursday with executives of tech companies and another will be held in the summer.

(Editing by Dave Zimmerman and Tim Dobbyn)