By Kevin Anderson
The complex system that the Chinese government uses to control the flow of information - known as the Great Firewall - has holes.
Protesters used SMS to organise anti-Japan marches
And these holes became more evident during the recent anti-Japan protests as a complex system of text messages, blogs, online instant messages, e-mail and bulletin board systems spread word about the marches.
The Chinese government and the Chinese people constantly play a cat and mouse game over the flow of information.
For every new restriction and technical door that the government slams shut, the Chinese people find a hack, a workaround or an entirely new way of communicating.
SMS: Tool for protest
For weeks leading up to the protests, messages coursed through the internet in e-mail, blogs and instant messages, and in short message service (SMS) texts over mobile phone networks.
On websites, people circumvented government filters by changing the spelling of the Chinese word for protest or using coded words.
Instead of a protest, they would call it a "spring outing", said Andrea Leung, who writes the blog T-Salon, which covers China and politics.
Chinese internet users also used social book-marking systems similar to del.icio.us and Furl in the United States, Ms Leung said.
Social bookmarks allow people to save and categorise a list of their favourite sites online.
Other internet users can see people's collections and subscribe to them. It helped other users quickly find information on the protests.
Protest organisers also used instant messaging networks and the internet phone and chat system called Skype, which the Chinese authorities cannot block, to pass along messages, she added.
SMS has proven its effectiveness in organising protests:
- Text message-obsessed Filipinos used SMS to help bring down President Joseph Estrada in 2001. Organisers say text messages accelerated the scandal-ridden Estrada's exit by two months to two years.
- In the wake of the 2004 Madrid bombings, protests were quickly organised using SMS calling for greater transparency in the investigation. It became known as "the night of short text messages".
- TXTmob, a free SMS broadcast service, was used to organise protesters in the US during the Republican and Democratic conventions and the Bush inauguration as well as helping drive the Orange Revolution in the Ukraine.
- In March, opposition leaders in Lebanon used telephones, e-mail and text messaging to organise massive anti-Syrian protests after the assassination of former Prime Minister Rafik Hariri.
It is not even the first time that SMS has been used to organise protests in China.
In December, 12,000 workers went on strike at the factory of a supplier of Wal-Mart.
The workers were not part of a union but used SMS and a blog to organise the strike.
There are more mobile phones in China than people in the US - some 350 million.
So when the authorities wanted to cool passions surrounding the anti-Japan protests, officials in Shanghai sent out a text message saying: "We ask people to express your patriotic passion through the right channel, following the laws and maintaining order."
Some protesters took this to be a message of tacit approval by the authorities, but others took it as a warning.
After weeks of protests, authorities have begun to crack down. More than 40 protesters have been detained, for what the authorities say was due to "disturbing social order".
Authorities in Shanghai warned protesters to obey the law via SMS
Most of those detained had been seen vandalising Japanese businesses.
One of the leading state run dailies, The Liberation Daily of Shanghai called the protests an evil plot.
The protests were "were used by the government in the middle term and then punished by the government after they used them", said Isaac Mao, one of China's pioneering bloggers.
Now mobile phone messages encouraging the protests are blocked and organising websites have been shut down.
"It's very difficult to find the original source today since many sites were ordered to shut down already," Mr Mao said.
Since 2002, internet service providers in China have had to sign pledges to monitor and censor traffic on their networks before they can operate.
Some 50,000 Chinese authorities do nothing but monitor traffic on the internet.
Blocked sites include those dealing with Tibet and Falun Gong, the BBC News website, the search engine Google and many blogs.
The Chinese people have embraced blogs as one way to enjoy, if not free at least freer, speech.
Mr Mao told a conference in December that in two years, the number of blogs China has mushroomed from 1,000 to 600,000.
To circumvent the Chinese firewall, Chinese bloggers are developing an Adopt a Chinese Blogger programme.
They hope to launch it soon and distribute the blogs over a number of different servers outside China so they are more difficult to block.
Many of the blogs in China do not stray from the official party line.
But Ms Leung said blogs are providing a new channel of information for people in China.
"From people's point of view, blogs are a lot more trustworthy because it comes from friends and family. It's a lot different than official media," she said.