By HENRY HOENIG in Beijing
By early February the people of Guangdong province had begun to panic, pouring into stores and clearing out supplies of Western antibiotics, vinegar and Chinese herbal tea, all of which were rumoured to fend off a mysterious virus the world would come to know as Sars.
But the virus had not yet been given a name. In fact, its existence had not even been acknowledged by the Chinese Government or by the media.
Yet by February 10 news of a "fatal flu in Guangdong" had reached 120 million people through text messaging, say some reports, and an untold extra number through email and internet chatrooms.
Chinese authorities had little choice but to acknowledge the outbreak and try to restore calm.
The Government had been taught a painful lesson about controlling the news in a burgeoning high-tech society.
That message would be repeated under similar circumstances two months later, when it was forced to admit it had been covering up the number of Sars cases in Beijing. In return, it has since sent a few painful messages of its own.
By mid-February, officials began complaining about the use of text messaging to spread "rumours", deeming them subversive activity and a threat to stability. Then they began arresting people.
By the end of May, 117 people in 17 provinces had been arrested and charged with disturbing social order by spreading Sars-related rumours, the Xinhua news agency reported.
The official People's Daily said on June 8 that 108 Falungong followers in Hebei province had been arrested for spreading rumours that hindered the Government's bid to control Sars, but did not state how those rumours were spread.
In the past, such arrests would probably have received little publicity. But this aspect of the Sars crisis and the following crackdown illustrate the enormous challenges Beijing faces in trying to maintain control of news and information in the age of communications technology, and the strategy it has developed to meet those challenges.
With its control slipping, the Government's response has been to combine cutting-edge technology with "low-tech Leninist" repression. Its technology allows it, for example, to search the country's entire volume of email traffic for words such as "Falungong", or to monitor any individual's text messages.
Anyone snared in its high-tech web can expect surveillance, intimidation, arrest and prison.
The publicity surrounding the arrests and prison sentences helps the Government achieve what experts say is its strategy of creating a climate of fear in which the people begin censoring themselves.
"Self-censorship is a much more effective way of controlling the internet," said University of Hawaii professor Eric Harwit, author of Shaping the Internet in China.
"They obviously can't arrest everybody who criticises the Government but they can publicise the penalties people could face."
Greg Walton, an expert on surveillance technology in China, said surveillance was crucial to the Government's goal of implementing self-censorship.
Of course, Beijing has hardly abandoned its efforts to censor the internet. But blanket censorship is reserved for extreme situations, and this fact reflects its long-standing dilemma: while it desperately wants to control the flow of news and opinion, especially dissent, it also wants an open, modern and efficient economy, including a state-of-the-art telecom and information infrastructure.
Its solution has been selective censorship of the news and increased monitoring of internet chatrooms, email, text messaging and individuals' surfing habits for "subversive activity".
Even before the Sars-related crackdown, at least 35 people had been arrested in the past few years for posting "subversive" writing on the internet, said Amnesty International. Five of them had been sentenced to a combined 41 years in jail.
"The cyberpolice, which have tens of thousands of members, are capable of arresting internet users anywhere in the country if they send a few messages considered 'subversive' or likely to 'jeopardise the state's security'," wrote the watchdog group Reporters Without Borders in a report released last month.
In March and April, the group conducted a month-long study of China's internet chatrooms during which a Chinese journalist with the BBC World Service repeatedly posted messages, many on controversial topics, to the most popular chatrooms, which draw millions of people daily.
Its report said less than a third of the controversial postings were allowed to remain on the sites and some never appeared at all.
Others took anywhere from 60 seconds to two hours to be removed by monitors.
"The survey showed that webmasters give priority to censoring messages that criticise the Government," the report said.
The Government has been able to implement such control over chatrooms by demanding they censor themselves.
In March last year it required all websites and domestic and foreign internet providers to sign a "self-discipline pact" obliging them not to disseminate "harmful texts or news likely to jeopardise national security and social stability, violate laws and regulations, or spread false news, superstitions and obscenities".
One topic subject to nearly blanket censorship in early April was Sars, said the group's report.
"On April 10, the researcher posted a message on a sina.com.cn forum containing the word Sars and just calling on the Chinese Government to work closely with Hong Kong to arrest the epidemic.
"The message did not appear. A second message about Sars was submitted to the site five days later. It met the same fate.
"The authorities seem to have asked the websites to add the term Sars to the long list of banned words. So no criticism of the Government's handling of the Sars crisis can be seen on the most popular sites."
Herald Feature: SARS
By HENRY HOENIG in Beijing