Despite those technological shortcomings, the dispatches by Wen and others helped mobilise public opposition to the paraxylene plant and earned the mainland activists one of their first victories of the new media age.

The Xiamen government ultimately backed down after more than 20,000 protesters filled the streets of the city in Fujian province for two days.

The plant project was called off, the first of several defeated by mass protests aided by social media.

Even in a country that has seen as much change as China over the past decade, few advances have had as much impact as the emergence of the internet.

During Hu Jintao's tenure as president, new media has become a major force behind the mainland's social, cultural and political development.

The internet and its ubiquitous microblogs not only allow unprecedented access to foreign news and culture. They also provide a forum for mainlanders to organise protests, debate issues and spread rumours - all with far less government influence and interference than the Communist Party would like.

It is not surprising, then, that Hu's government has in recent months taken steps to rein in the internet and strengthen China's "Great Firewall".

But events around the world suggest that the new media genie - once free - is hard to put back in the bottle.

How the government copes with the rising force of new media may come to define the tenure of Vice-President Xi Jinping , who is widely expected to become the next leader at the party congress next month.

"In the age of new media, everyone could be a potential source of news or information and everyone can make an impact by having their voices heard," said Xia Xueluan , a sociologist at Peking University.

Social media's increasing influence may be inevitable as smartphones put internet access in the palm of everyone's hands.

The number of internet users on the mainland increased 12 per cent to 513 million last year, according to the China Internet Network Information Centre.

That is a larger online population than the United States and India combined, even though the overall share of internet users on the mainland - 38 per cent - lags far behind its neighbours, such as Japan and Korea.

Since 2009, an increasing share of internet traffic has taken place on weibo - microblogs modelled on global social-networking site Twitter.

The most prominent site, Sina, recently reported having 300 million registered users alone, quickly closing in on Twitter's estimated 500 million.

While weibo accounts have allowed some activists to organise illegal protests, they have also revolutionised other, more innocuous forms of public outreach on the mainland, such as charitable fundraising and recruiting drives after disasters.

Xia, the Peking University professor, pointed to the unprecedented outpouring of volunteerism after the devastating Sichuan earthquake in May 2008 as an example of how social media was changing Chinese society.

There are smaller examples, too. In April 2010, Deng Fei, a journalist for the mainland-based , started a weibo-based campaign to raise money for school lunches after learning about an impoverished school in Qianxi county, Guizhou province, that was serving pupils nothing but cold water.

The campaign has since raised more than 30 million yuan (HK$36.7 million) to help feed 16,000 pupils at 200 rural schools.

It also helped prod the central government to allocate 16 billion yuan annually to fund a lunch programme for 26 million rural students. Deng, 34, has been empowered as well. He saw his number of weibo followers grow to 2.3 million from about 160,000 before he launched his campaign.

He is now using that platform to raise money to buy medical insurance for rural pupils.

"How could an individual like me possibly have so much power and appeal without weibo?" Deng said.

That is the beauty of social media, said Wen, the citizen journalist involved in the Xiamen protest. It gives people strength in numbers and encourages more of them to speak up and stand up to the authorities.

Correspondingly, it has weakened the government's ability to control public opinion and intimidate those who step out of line, he said.

"A relatively free flow of information, which is guaranteed by new media technologies, will certainly lead to an awakening to equality and rights as well as ensuing action to secure them," Wen said.

In particular, he noted the grassroots effort to free blind lawyer Chen Guangcheng from his months-long house arrest in Linyi village, Shandong province.

Chen fell foul of the local authorities by exposing forced abortions used to enforce the one-child policy.

Organised online, droves of civil activists, academics and ordinary citizens tried to break the security blockade near his home. Eventually, even star Christian Bale got in on the act, drawing global headlines. After Chen ultimately escaped and received sanctuary at the US embassy and in Beijing, the public support for his plight was so strong that the central government decided to grant his request to accept an academic fellowship in New York.

"This represented a significant shift in the civil movement on the mainland - a shift from a mere struggle for material rights to [broader] human rights and a shift from a fight for people's own rights to the rights of others," Wen said.

In some cases, the government has responded to the pressure in a positive way, with agencies, particularly at the lower levels, becoming more transparent and more responsive to public complaints.

But they have also taken steps to weaken the weibos, such as compelling companies to shut down the accounts of bloggers who become a problem.

In March, weibo providers began enforcing a government order requiring weibo users to register their real names, removing the protection of anonymity.

It remains to be seen how much such restrictions will limit the political strength of social media. Weibo accounts are overflowing with messages criticising government officials and urging people to speak up.

Professor Wu Hui , of the Central Party School, acknowledged that social media had improved free speech and access to information, and argued that some regulation was necessary to prevent rumour-mongering and attacks on the government.

But he said the government's best approach for dealing with social media was to use it to interact with people.

"While the new media technologies certainly need to improve, the governments also have their own imperfections," Wu said. "If the governments can improve their governance, the chance of negative news spreading via new media technologies is smaller."

Michael Anti, a mainland-based commentator specialising in new media, said he believes government efforts to blunt the impact of internet activism are succeeding more than people realise.

Anti said he has seen a marked drop in the scale and frequency of rights-related civil campaigns in recent years. He attributed the drop to crackdowns against activists who cross the line and cause too much trouble, including dissident artist Ai Weiwei , environmental campaigner Tan Zuoren and civil rights lawyer Xu Zhiyong.

The weibo accounts for many prominent activists and opinion leaders are also subject to frequent censorship, suspension and closure, Anti said.

Wen Yunchao, for example, estimated that he has had more than 40 weibo accounts closed.

Anti said that he would rather self-censor his own microblog and save the hassle of having to open one account after another.

"Don't forget they have the control of the servers and they could always do something if they feel it's necessary," he said. "It's as simple as that."