The Sars crisis in China has provided intriguing evidence on how the use of modern communications - particularly the internet and mobile technology - can be used to break down the walls of official secrecy. When China sought to conceal the spread of the virus, millions of Chinese turned to their keyboards and mobile phones to access banned foreign reports and censored domestic information. Internet traffic rose by 40 per cent and mobile phone traffic by 30 per cent. It was the latest round in an ongoing struggle between a long-entrenched regime and a newly emerging civil society for freedom of electronic information, which has intensified in the past two years. The state apparatus has won some heavy-handed victories. More than 20 journalists and civil rights campaigners have been detained on charges such as 'using the internet to subvert state power'. Dozens of foreign websites are routinely blocked to anyone attempting to access them through a Chinese server. Some experts calculate that China spent US$200 million last year on new surveillance equipment. Yet a relatively unfettered traffic in electronic news and comment continues to grow at a pace which no amount of technology can control. Most users observe some commonsense principles of self-censorship: no one is going to criticise a party leader by name or defend the banned Falun Gong sect. There is, however, a mass of information and discussion on sensitive social issues such as the widening gap between rich and poor, official corruption, discrimination against migrant workers and HIV-Aids. Some are copied from overseas websites run by dissident Chinese to which direct access is banned, but the majority reflect a growing freedom of debate. Two notable examples in the past year are the Nongyou (Farmer's Friend) and the Aizhi (HIV-Aids knowledge) sites. Nongyou was set up by Li Changping, a former local rural cadre in Hubei province who became known nationally for denouncing the high level of illegal taxes levied on most peasants. Postings on Nongyou include an essay by a university researcher on the high suicide rate of rural women - still too sensitive a subject for most official media. Other contributions call for more investment in the countryside and defend the rights of migrant workers. The Aizhi site, founded by HIV-Aids activist Wan Yanhai, operates in a politically higher-risk field, but has so far survived harassment, including the temporary arrest of Mr Wan last year. It is best known abroad for championing the cause of the peasants in Henan province who were infected with the HIV virus by commercial blood collectors. Aizhi has incurred official wrath by publishing evidence of the connivance of the provincial health authorities. Material from Nongyou and other social action websites is often passed on by individual emails or posted on bulletin boards. There is also a crossover of material between these sites and a handful of adventurous print newspapers such as the Nanfang Zhoumo. In a recent example, protests at the death in custody of Sun Zhigang, who was held by police in Guangzhou, were picked up by newspapers after circulating widely on the web. Material also flows freely between the social action groups and a number of academic sites such as Xue er Si (Study and Thought), run by Yang Zhizhu, a Beijing law professor. The result is a continuum of argument and dissent, from the most cautious to the most outspoken, which transcends China's national borders. Current issues now being widely debated include China's extensive use of the death penalty, the alienation of the Chinese intellectual and the government's mishandling of the Sars crisis. China's web censors devote most of their effort to blocking access to foreign-based human rights and dissident sites which can be labelled clearly as 'anti-Chinese', such as the New York-based Human Rights in China or China Spring publications. The controls on foreign media vary in intensity: some, including the Washington Post and Reuters, were 'liberated' last year, but audio links to the BBC and Voice of America Chinese-language broadcasts are still rigorously blocked. Considerable effort goes into barring access to 'proxy servers' that can be used to mask entry to forbidden sites. Use of the Google search engine 'cache' facility for the same purpose has also been blocked. These blocking actions are, no doubt, reported to higher authorities as evidence of success in the struggle against 'poisonous weeds'. The operation is run by the Ministry of State Security and is an embarrassment to the Chinese foreign ministry, which refuses to admit it exists. Although an intensely irritating form of censorship, it is an increasingly futile exercise as far as the Chinese people are concerned. The government is engaged in a losing battle against a news-hungry and increasingly sophisticated people who are finding creative ways to get past the hi-tech word-based filters. Mao Zedong was right when he said that the course of battle was determined not by machines but people. John Gittings is China specialist at The Guardian. His latest book is China Through the Sliding Door. This article appeared in YaleGlobal Online ( www.yaleglobal.yale.edu ) and is reprinted by permission. Copyright 2003 Yale Centre for the Study of Globalisation.