BEIJING — The order by China's Ministry of Industry and Information Technology was unprecedented in scope: All personal computers sold in the country as of July 1 would have to include government-sponsored Internet filtering software.
But just how the plan, which would potentially affect hundreds of millions of computer users, would be carried out remains unclear. The rules, issued last month but made public this week, require computer manufacturers to install software whose stated aim is to shield minors from pornography and other "harmful" material.
Proponents of Internet freedom worry that the plan would expand the reach of one of the world's most stringent domestic censorship programs. Restricted access to politically sensitive material is a way of life in China. YouTube has been blocked since April.
Officials say the software, known as Green Dam Youth Escort, has already been downloaded 3 million times since March and has been used in about 2,300 schools. "Green" has become a euphemistic term to describe nonthreatening Web surfing.
Zhang Chenmin, founder of Jinhui Computer System Engineering Co., the company that developed the software, said he wouldn't know how to expand his program to include blocking subjects the government deemed politically subversive.
He said he had spent the last five years developing a program that identifies nudity online, which won him a government bid.
Such claims leave experts skeptical.
Xiao Qiang, director of the China Internet Project at UC Berkeley, said Beijing fears losing control of the Internet and has been discussing software-driven tools since 2002.
Meanwhile, PC makers must determine how to include it on their devices in the coming weeks. That includes U.S. manufacturers with major presences in China such as Hewlett Packard Co. of Palo Alto and Dell Inc. of Round Rock, Texas.
"The question is how practical this is going to be from a sales standpoint," said David Wolf, president of tech and media advisory firm Wolf Group Asia Ltd. "There's a lot of inventory packed in advance. I'm not sure the Chinese government has a clear understanding of this."
U.S. technology firms will again be asked to comply with Chinese laws that conflict with U.S. standards of freedom. Google Inc., Microsoft Corp. and Yahoo Inc. have been accused of doing Beijing's bidding by blocking some Internet access and sharing information.
"It will put American companies in an uncomfortable situation," Wolf said. "You have to do business according to state law. It may be considered unsavory elsewhere. But it's part of the price of doing business here."
A Hewlett Packard representative said the company was monitoring the situation, but declined to elaborate.
Dell did not respond to an interview request, nor did China's chief computer maker, Lenovo Group.
The U.S. government has been meeting with industry groups to discuss the issue, said Susan Stevenson, a spokeswoman for the U.S. Embassy in Beijing.
"We would view with concern any attempt to restrict the free flow of information," Stevenson said. "Such steps would be incompatible with China's aspirations to build a modern, information-based economy and society. The U.S. is concerned about actions that seek to restrict access to the Internet as well as restrictions on the internationally recognized right to freedom of expression."
Chinese blogs batted around ways to circumvent the Green Dam, while others mocked the government's plan.
"No problem," wrote a blog poster named cy123 on Douban.com. "Mainland China has netizens with superb skills and techniques. After the company [Jinhui] earns their share, there will be many cracked versions" of the program.
Nicole Liu and Yang Luzi in the Times' Beijing bureau contributed to this report.