Many of the websites issued apologies and promised to clean up, setting up hotlines for complaints. The CIIRC has updated the results of the campaign on its website to inform the public of the latest progress.

Profit drive

"It's not difficult to filter vulgar and harmful content on the Internet in terms of technology," said an industry insider. He said search engines like Google and Baidu can raise their Web page identifying level to keep illicit pages out of search results. "You only have to pay the search engine companies to include the offensive Web pages in their search results," he added.

"Some Web masters chose to turn a blind eye to harmful content for the sake of profits, as it brings in a lot more hits and traffic," Lin Yi, Deputy Chief Editor of the entertainment section of Qianlong.com, a local news portal in Beijing, told Beijing Review.

Three major reasons contribute to the problem of morally harmful Internet content, according to Internet experts. Driven by profits, some websites deliberately publish improper content to attract network traffic, ignoring social responsibility and law.

Some websites lack tight control and supervision over their active columns, such as blogging and podcasting, giving rise to the rampant spread of harmful content. On the part of netizens, some lack the self-discipline to stop publishing and spreading this content.

"Nowadays China shows a more tolerant attitude toward nude art. The blurry line between nude art and pornography makes it difficult to regulate the enormous amount of pictures on the Internet," said Min Dahong, a senior Internet researcher.

Healthy development of the Internet in China cannot take place without strong supervision, said Min. People involved in the Internet business need to be more disciplined and always bear a sense of social responsibility in their minds.

"It's not practical to impose a content- rating system on the Internet as the movie rating system in China is still not available yet," said Min.

China can borrow the experience of some developed countries to effectively monitor the Internet, said Xia Qingfan, a professor of news and communication at Wuhan University.

"Website operators should be strictly regulated and should be requested to set up different authorities to keep minors away from browsing certain content that is not suitable for them," Xia said.

China's Internet users hit 298 million in 2008, overtaking the United States as the nation with the world's largest online population, according to the latest figures released by the China Internet Network Information Center.