BEIJING, China - China, which employs an army of censors to police the Internet, has also deployed legions of "web commentators" to get the government's message out -- in a crafty but effective way.
With nearly half a billion people surfing the net in China, more than half of them using microblogs, the Internet has quickly become a vital forum for debate in the world's most populous country -- and a major sounding board.
That fact has obviously registered with the country's Communist leaders, who pay careful attention to the conversations that unfold online despite the heavy government restrictions on what can and cannot be discussed in cyberspace.
Enter the "web commentators" who, either anonymously or using pseudonyms, spread politically correct arguments -- many of them for money. Who are these high-tech propaganda wizards, infiltrating blogs, news sites and chat rooms?
"It is very mysterious... these people don't talk to the media! Everyone is just guessing," Jeremy Goldkorn, editor of the China media website Danwei.org, told AFP.
For high-profile independent Chinese blogger Li Ming, the army of pro-government web commentators must number "at least in the tens of thousands".
Renaud de Spens, a Beijing-based expert on the Chinese Internet, told AFP that most of them were likely students "doing a basic cut-and-paste job" -- a mindless task, "just like if they took jobs in telemarketing".
Some of those students are trying to improve their chances of gaining a coveted party membership.
But the group of web spin doctors also includes civil servants and employees of state-owned firms -- and even retirees and housewives keen to support the party line.
De Spens notes that the system is far from centralized.
"The provinces, cities, districts and work units all rally their own small armies to infiltrate the Internet in a subtle way," he said.
In 2010, the Global Times reported that Gansu province alone was looking to recruit 650 full-time web commentators "to guide public opinion on controversial issues".
Amnesty International secretary-general Salil Shetty in March warned that countries like China and Iran were investing "considerable resources into pro-government blogs" in an effort to cement state power.
About five years ago, when blogs first took off in China, the country saw its first "wu mao" (50 cents) -- net commentators paid by the message to spread the official party line.
But according to De Spens, they were progressively replaced by a new breed of online government workers -- who are more subtle and more effective.
"It certainly seems that they have gotten more sophisticated," Bill Bishop, co-founder of the news site MarketWatch.com who now blogs about the Internet in China, told AFP.
"They have been doing this for years. They have been very good at learning how to use the Internet."
Instead of posting simple slogans such as "Long live our leaders" or "Long live the party", the web commentators develop detailed, rational arguments.
On the crisis in Libya, they have published comments slamming the hypocrisy of the West in launching air strikes against the regime of Moamer Kadhafi -- a campaign opposed by Beijing -- saying they are only interested in oil.
"There is a subliminal effect -- the message gets into people's heads, even the dissidents, especially the arguments that make sense," De Spens said.
Other recent hot topics include the US raid that resulted in the killing of Al-Qaeda leader Osama bin Laden, China's efforts to build an aircraft carrier, equal opportunity in education, food safety and vegetable prices.
On Sina Weibo -- China's answer to Twitter, which is officially blocked on the mainland -- the pro-government netizens are working on tainting the reputation of detained artist and activist Ai Weiwei.
Web commentators "are paid based on the number of comments they post, and they can also get a bonus if one of their posts is named one of the most popular on the site," Li explained.
Experts are divided on the overall effectiveness of the massive web operation.
"On the main hot topics, three days into the debate, only the propaganda remains online," creating a "false general opinion" which the great majority of web users will blindly follow, De Spens said.
"That is the major success of Chinese propaganda."
But Goldkorn counters that Chinese web users are "quite savvy... they tend not to trust anyone."
"When there are large numbers of comments that are toeing a government line, it certainly makes it more difficult for people who disagree to have their voice heard above the noise," he nevertheless acknowledged.
The operation does have an unfortunate downside for the leadership -- independent pro-government web users are often accused of being "wu mao", a term that has become an insult.