Like many web surfers in Beijing, Zhang Rui browses adult websites around midnight. But while others download content, she helps remove it.

Zhang, the mother of a 10-year-old, is one of a group of Beijing mothers helping the government censor content in China's chaotic cyberspace.

As part of a year-long national campaign to prevent teenagers from accessing "harmful content", the Beijing Association of Online Media initiated a special panel of "mom judges" two months ago, inviting about 150 of them to help officials find "obscene and harmful content".

Some critics have said instead of raising parents' awareness of children's online habits, the initiative might cause the embarrassing scenario of a mother reporting her own son or daughter to the authorities.

The potentially sensitive nature of the job has likely discouraged many applicants and fewer than 50 mothers signed agreements with the authority during the program's launching ceremony.

"Maybe some of them don't feel comfortable talking about online pornography in front of television cameras. Maybe they would rather help children in their own ways, without joining any government organizations," said Zhang, 38, two months after starting her new volunteer job.

The group of mothers includes celebrities, social campaigners, education experts and homemakers. Some of them have been involved in other government-led campaigns and are accustomed to making speeches and appearing on television.

But Zhang, a college professor, said she prefers to remain as low-key as possible in her new role.

"I don't want my colleagues to know too much about my private life," said Zhang.

Zhang also said she has only told a few of her closest friends about her involvement with the project.

"We don't want to be considered a group of political slogan chanters - we are more like a committee of concerned mothers," said Wei Ruirui, 31, another mom judge.

Wei, a doctoral degree candidate and the mother of a 7-year-old boy, also tried to keep her new identity secret from friends. But after she gave interviews to Beijing papers, some of her friends called her, curious to know whether it was true that she had never watched porn.

"The way they questioned me made me feel I did something wrong," Wei told METRO. "Isn't it normal for worried mothers to take some action to protect both their own children and others'?"

Apart from the inconvenience the job has caused, the mother judges said they believed their work would make a difference.

Zhang said she spends about an hour a day tracking down dirty content and in that hour she sometimes finds extremely explicit material.

"My son also once told me about a game called 'Breaking Into The Girls' Dorm'," she said. "The game is far too explicit and exposes teenage boys to far more than they need to know at their age, in an inappropriate and demeaning manner."

The rest of Zhang's browsing includes searching through online photo collections and looking for threads containing sexual implications on popular social networking sites and forums.

"I only search for the stuff after my boy goes to sleep. I don't want him to know about the ugly details of the adult world before he can fully comprehend it," said Zhang.

Wei said she does not have time to troll through adult content online. But she translates Internet regulations and restrictions from developed countries, which she downloads from her school library.

Understanding other countries' approaches to screening minors from obscene content might help China form a cohesive plan to deal with the problem.

"I believe clear and detailed laws are the best solution to the Internet confusion in our country," she said.

The Ministry of Industry and Information Technology released 13 items, such as excessive exposure of the body, images and words with sexual implications, and pornography, to define "obscene and harmful information". The authorities also said violent content, homosexual content, unsanctioned religious content and politically sensitive content should be restricted in the cyber world.

Li Yizhong, China's minister of industry and information technology, said in Beijing this week that authorities will speed up the campaign to shut websites with harmful content.

The minister also emphasized that China's Internet policy remains "open".

Zhang said she does not always need to refer to the "13 rules" to pass judgment. "Sometimes, the content does not meet any of the requirements, but my friends and I know that it is not suitable for teenagers," she said.

The last time Zhang removed a post was in January, when she noticed a post written by one of her male friends on the popular social networking website Kaixin001.

Zhang first wrote a message to her friend, asking him to delete the post. He refused at first, saying it contained nothing sexual, but after Zhang's friend also wrote to him, he finally removed it.

Without a rating system for online content and related laws on cyberspace management, both parents and authorities have found it difficult to regulate online content.

"Content classification is one of the solutions to regulate China's 300 million Internet users, almost half of whom are teenagers and young adults," said Zong Chunshan, a Beijing-based education specialist.

"But our laws on new media such as the Internet lag far behind the actual expansion of the industry. It will take a long time before any real progress is made."

Volunteer groups and local-level campaigns are a good way to start, but authorities should learn not to discourage the enthusiasm of the public, said Zong, who has campaigned years for a mother-oriented online monitoring group.

"Authorities don't like seeing civil groups operate without a nod from officials, so they interfere and make good deeds complicated," said Zong. "It should be the other way around: local forces, such as mothers, should take active role in public affairs and advise the government on issues such as Internet management."

No more sessions for the mothers have been held since the launching ceremony in December. Zong, who is an adviser to the campaign, said the authorities have not come up with any new ideas on how to operate the group.

Zhang said she will finish her one-year contract with the authorities, but she is unsure whether she will sign another one.

"If I find the group to be a tool manipulated by some officials and not a mother-oriented campaign, I may quit," she said.