BBC News, Beijing
The Chinese authorities have launched a fresh campaign to get rid of unhealthy, vulgar and pornographic content on the internet.
The authorities have also published the names of 19 websites that have failed to heed requests to get rid of unsuitable material.
These include Google and China's top internet search engine, Baidu.
These websites could be closed down if they do not delete the offending material, according to one official.
China believes it has a duty to protect public morality.
Officials seem to be particularly concerned about pretty girls in suggestive poses that can be accessed through various websites.
They fear this and other "unhealthy" content could damage young people's physical and mental health.
Excuse for censorship?
The new campaign is being co-ordinated by a total of seven government ministries.
They have published the names of 19 offending websites that have so far ignored warnings to get rid of unsuitable content.
These websites are being told to clean up their websites - or else.
"We will continue to expose, punish or close down websites that have a lot of vulgar content," said one official, Cai Mingzhao, speaking on Chinese Central Television.
Officials also want the public to act as their eyes and ears in this campaign against sleaze.
But there is a fear the crackdown will not just be restricted to vulgar material.
The Chinese government keeps a firm grip on the internet, blocking certain websites and censoring some sensitive material.
This campaign could be used as an excuse to stifle political dissent in a country that allows little public criticism.
One of the websites that has been publicly criticised, Tianya, is popular with people who post their criticisms of the government