In Beijing, a pregnant woman, Zeng Jinyan, blogs almost daily about her married life. This, however, is no tale of cosy domesticity. She posts photographs of the cars used by the state security officers who follow her and her husband every time they leave their house.
Last week, she described going for a walk in the park and chatting with her husband about their unborn child. Then, in frustration, "I looked back at the state security officers whose keys were rattling at their waists, and I said to them, 'Aren't you ashamed? Keep further away from us!'"
Zeng has blogged about how, on 18 May this year, she and her husband, Hu Jia, were followed by plainclothes police to a routine 16-week pregnancy check-up at the hospital. Then, on their way to the airport to fly to Europe, they were detained by eight police officers and questioned for four hours. Since then, they have been under constant state surveillance and banned from travel. Zeng has blogged bitterly about her confinement and the nature of a government that chooses to treat her and her unborn child in this way.
Zeng and Hu are campaigners for the rights of people with HIV/Aids. They are just two of a small but growing group of activists in China who are beginning to use the power of the blog to reach a huge readership.
Xiao Qiang, editor of the US-based China Digital Times, an online monitor of Chinese news and internet developments, points out that "censorship's most direct impact on blogging is that there is a lack of 'political bloggers' in the Chinese blogosphere". Pure politics is simply too dangerous. The small number of campaigning bloggers are not dissidents; they do not call for the overthrow of the Communist Party. But they are at the forefront of debate on specific social issues.
The country's Communist leaders fear their power, but for all the government's cyber-policing, the bloggers are proving almost impossible to control. Last year, the official People's Daily reported that there were more than 30 million bloggers in China, and that their numbers were set to grow by a further 60 million in the next year.
Of course, many blogs fall by the wayside and, like bloggers everywhere, many Chinese bloggers are more interested in film stars and sex than in social activism. Portals use celebrity blogs to attract traffic, but the lines between a politically sensitive blog and a useful revenue-generator in a fiercely competitive portal market in China are being blurred. What is clear is that in China, where free speech is suppressed so vigorously, blogging has become a cyber civil society.
The phenomenon of activist blogging is "unstoppable", says John Kennedy, the Chinese language editor at Global Voices Online. "In the absence of a normally functioning legal system, the internet is where the engaged public is coming to consensus on what the future of China is going to look like."
The mainstream media remain under the control of the Propaganda Department, the country's media police, which issues secret diktats concerning what may and may not be covered. Most recently, The Washington Post reported, food safety scandals, murder and riots have been declared off limits.
Among many Chinese there is a thirst for debate, and for access to information that has not been through the wringer of the Propaganda Department. In several cases journalists themselves are embracing the blog, and some newspapers are lifting articles and columns directly from blogs to print in their pages.
In May, the journalist Lian Yue, in the tropical city of Xiamen, blogged about the horrors he thought would be wreaked on his peaceful beachfront city by a petrochemical plant the government was desperate to see built. A few days later, someone sent an anonymous text message saying the construction of the plant would be like dropping an atom bomb on Xiamen, and SMS messages started to fly around the town. This launched the biggest middle-class protests in China's modern history.
A media blackout was imposed on the demonstrations, but to the dismay of the Propaganda Department the issue developed into a perfect storm of blogs, SMS messages and internet bulletin-board postings. Several bloggers from the independent collective Bullog attended the demonstration and sent live SMS updates direct to a colleague who had stayed at home at his computer, and he posted their updates minute by minute. They soon attracted so many readers that Bullog's host server was unable to keep up. Several people have been arrested for spreading the word – the internet police have technological and administrative methods to demolish a blogger's anonymity.
Xiao Qiang writes: "Facing these independent voices, the old ideological machine starts to crumble. Within society, bloggers like Lian Yue are seen as more credible voices than propaganda officials."
In June this year, the internet once again deeply embarrassed the Communist Party and set the agenda for national news. The parents of kidnapped children in Henan posted a letter to an internet site begging for help in finding their offspring, and it was instantly transmitted in the form of blogs and SMS messages across China. Soon, the mainstream media had no choice but to investigate the issue.
When the first television pictures were shown of battered and beaten teenage boys being used as slave labour in brick kilns and mines, the government itself launched an investigation. It was found that local police and local officials were profiting from the trade in kidnapped children. It was the sort of story that the mainstream media might well have been ordered to hush up, but the firestorm of blogger reports forced them to respond.
After the Xiamen protests, the government tried to ban anonymous postings and to insist on real-name registration. Ever since the dawn of the blog, the Propaganda Department has tried closing them, blocking entire domains and imposing keyword filters that ban several hundred sensitive words, only a small number of which are obscenities. The keywords include the names of many of China's leaders, as well as references to the Tiananmen massacre of 1989, and words relating to Falun Gong, the religion that Beijing has branded a cult.
Posts containing these words are removed by censors employed by the host site. Sometimes the blog itself is eliminated. But some filtering systems are more efficient than others. Character splitting is one way to evade the censors; because Chinese characters are made up of several parts, these can be split apart on the page. This strategy fools an automatic keyword filter, which sees only nonsense words, but is easily digested by a reader who knows what is going on. Bloggers are also working on systems that convert sensitive words into images, thereby subverting the filters.
Last year Hao Wu, a well-known blogger, was arrested and detained for 140 days. His blog, Beijing or Bust, was mildly critical of the Chinese government. He blogged about his plans to make a documentary about Chinese Christians, and the obstacles he was encountering from religious officials in Beijing.
After his release, he blogged about inviting his friends for a drink to celebrate his freedom. "I'm not one of those who fight to break the shackles," he wrote. "But I can dance. Dance with my shackles. Dance with my bondage after the shackles."
Catherine Sampson's novel, The Pool of Unease, set in Beijing, is out now (Macmillan, £12.99). She blogs about her work and life in Beijing at http://www.catherinesampson.com/pages/blog/index.aspReuse content