BEIJING (AP) -- China's authoritarian government has backed away from an order to load Internet-filtering software on every new computer after a major outcry by citizens used to the relative freedom of online life.

Legal challenges, petitions and satirical cartoons had been part of a broad grass-roots effort to scuttle the initiative since it was announced earlier this month.

A Ministry of Industry and Information Technology official told The Associated Press on Tuesday that Chinese computer users are not required to use or install the Green Dam Youth Escort software — though the software will still come pre-installed or be included on a compact disc with all PCs sold on the mainland from July 1.

"The use of this software is not compulsory," said the official, who would not give his name as is customary with Chinese officials.

Executives from the company that created the software had said earlier that it was possible to uninstall Green Dam, but it was not clear until Tuesday that the government's new regulation would not penalize people who chose not to use it.

The change marked a small victory for a burgeoning anti-censorship movement in China. Internet users in particular have expressed growing frustration with official efforts to monitor and restrict online content. China's Internet has emboldened public opinion and given citizens the tools they need to mobilize around a cause, such as exposing corruption or halting a project believed threatening to public health.

Although the government says the software is aimed at blocking violence and pornography, users who have tried it say it also prohibits visiting sites with discussions of homosexuality, mentions of the banned Falun Gong spiritual group and even images of pigs because the software confuses them with naked human bodies, according to Hong Kong media reports.

Petitions and at least one legal challenge have also been launched. Beijing lawyer Li Fangping submitted a request to the Ministry of Industry and Information Technology last week demanding a public hearing on the "legitimacy and rationality" of forcing computer makers to include the software with every unit sold. Li said Tuesday he had yet to receive a response from the ministry.

Yang Hengjun, 45, a well-known blogger and novelist based in the southern city of Guangzhou said Chinese parents today are more inclined to demand a free and open Internet over a free but flawed pornography filter.

"On the Internet, we can do many things and we can criticize the government. This was not possible before," he said. "Having used the Internet like this, we are now unable to tolerate having it restricted."

Yang cited the central role of the Internet in exposing and criticizing several recent scandals of particular concern to parents, such as the contamination of infant formula with the industrial chemical melamine and research that showed schools collapsed more easily than other buildings during last year's massive Sichuan earthquake.

PC makers will determine if the software is pre-installed on the hard drive or enclosed on a CD and will be required to tell authorities how many computers they have shipped with the software.

Tests of Green Dam by independent researchers have also found that the software makes computers more vulnerable to security threats.

Computer scientists at the University of Michigan said in a report last week that the program contained "serious security vulnerabilities due to programming errors," and recommended users protect themselves by uninstalling Green Dam immediately.

The Michigan report also said that a look at Green Dam's coding seemed to show some of it had been lifted from an American-made filtering program CyberSitter, raising questions about intellectual-property violations related to the software.

The maker of that program, Solid Oak Software of Santa Barbara, Calif., plans to seek a court injunction, but acknowledged that it's new legal terrain for the company.