Durbin’s initiative follows Google’s announcement that it had been the victim of cyber attacks aimed at gaining access to the email accounts of Chinese human rights activists. Google has said it is considering pulling out of China because of the attacks and what the company called “attempts over the past year to further limit free speech on the web.”

Only two weeks ago, U.S. Secretary of State Hilary Clinton called on American technology companies to make a “principled stand” against attempts at censorship.

Sen. Durbin, Chairman of the Judiciary Subcommittee on Human Rights and the Law, said his hearing next month will feature testimony from Google and other companies about their business practices “in internet-restricting countries,” as well as from high-ranking Obama Administration officials about the Administration’s efforts to promote internet freedom.

“I commend Google for coming to the conclusion that cooperating with the ‘Great Firewall’ of China is inconsistent with their human rights responsibilities,” Durbin said. “Google sets a strong example in standing up to the Chinese government’s continued failure to respect the fundamental human rights of free expression and privacy. I look forward to learning more about whether other American companies are willing to follow Google’s lead.”

Durbin’s letter asks each firm for details of its business in China, and what, if any, measures it will implement to ensure that its products and services do not facilitate human rights abuses by the Chinese government.

This week’s letter also follows up on a letter that Durbin sent last year, urging technology firms to join a voluntary code of conduct known as the Global Network Initiative (GNI). The code of conduct, which regulates the actions of technology firms operating in countries that restrict the internet, has been backed by Google, Microsoft, and Yahoo! and a number of leading socially responsible investment firms.

Durbin’s office said the list of companies that responded to his previous letter included Apple, AT&T, Cisco, Dell, eBay, Facebook, HP, McAfee, News Corp, Nokia, Nokia Siemens, Siemens, Skype, Sprint Nextel, Verizon, Vodafone, Websense.

According to Senator Durbin’s office, companies that did not respond to his previous letter were Acer, Juniper, Toshiba, Twitter; companies that “partially responded” to his previous letter were Fortinet, Lenovo, Motorola.

That’s one of the messages delivered today by U.S. Secretary of State Hilary Rodham Clinton in a major speech that focused on attempts by some national governments to stifle the “free exchange of ideas” among their citizens.

.Coming only a week after Google announced that it had been the victim of cyber attacks aimed at gaining access to the email accounts of Chinese human rights activists, Mrs. Clinton called on Chinese authorities to “to conduct a thorough investigation” of the attacks and report  “transparent” results.

Mrs. Clinton, speaking to an audience at the Newseum journalism museum in Washington, D.C., seemed to endorse Google’s threat to pull out of China because of the attacks and what the company called “attempts over the past year to further limit free speech on the web.”

She also issued a direct challenge to information and technology companies doing business in countries where governments seek to censor Internet communication.

We feel strongly that principles like information freedom aren’t just good policy, not just somehow connected to our national values, but they are universal and they’re also good for business.

To use market terminology, a publicly listed company in Tunisia or Vietnam that operates in an environment of censorship will always trade at a discount relative to an identical firm in a free society. If corporate decision makers don’t have access to global sources of news and information, investors will have less confidence in their decisions over the long term. Countries that censor news and information must recognize that from an economic standpoint, there is no distinction between censoring political speech and commercial speech. If businesses in your nations are denied access to either type of information, it will inevitably impact on growth.

Increasingly, U.S. companies are making the issue of internet and information freedom a greater consideration in their business decisions. I hope that their competitors and foreign governments will pay close attention to this trend.

And:

For companies, this issue is about more than claiming the moral high ground. It really comes down to the trust between firms and their customers. Consumers everywhere want to have confidence that the internet companies they rely on will provide comprehensive search results and act as responsible stewards of their own personal information. Firms that earn that confidence of those countries and basically provide that kind of service will prosper in the global marketplace. I really believe that those who lose that confidence of their customers will eventually lose customers. No matter where you live, people want to believe that what they put into the internet is not going to be used against them.

And censorship should not be in any way accepted by any company from anywhere. And in America, American companies need to make a principled stand. This needs to be part of our national brand. I’m confident that consumers worldwide will reward companies that follow those principles.

Mrs. Clinton said she was also encouraged by the work of the Global Network Initiative, a voluntary effort by technology companies “who are working with non-governmental organization, academic experts, and social investment funds to respond to government requests for censorship.”   Google, Microsoft and Yahoo! are among the few U.S. technology companies that have agreed to the principles of the Global Network Initiative.

Disclosure: Business Ethics Editor and Publisher Michael Connor is also Executive Director of the Open Media and Information Companies Initiative (www.openmic.org), a non-profit media advocacy organization that regularly addresses issues related to an open Internet and corporate responsibility.