CLEAN CONTENT: A boy surfs the Internet under the guidance of a member of staff at an Internet cafe in Changsha, Hunan Province. China launched a crackdown on vulgar and harmful Internet content in January (LONG HONGTAO)

China declared war against indecent and harmful Internet content by announcing a third list of 17 websites criticized for "publishing indecent and vulgar content" in mid-January, as part of a month-long drive to stamp out online porn.

The sites were urged to immediately delete obscene or erotic information and were threatened with closure if they ignore the warning.

Previously, the country had blacklisted 33 websites on two lists, including search engines Google and Baidu, the country's major web portals Sina, Sohu and NetEase, as well as blog service hosting websites and Internet forums such as Tianya. Some 175 other websites have been shut down.

These websites were accused of containing "large amounts of indecent and vulgar content that violates social morality and damages the physical and mental health of youths."

The campaign was launched in early January by the State Council Information Office, the ministries of Public Security and Culture and four other government agencies.

Public distribution of pornography is illegal in China. The country regularly launches Internet clean-up campaigns, but the latest crackdown is the first in which the government has targeted heavyweight companies such as Google and Baidu.

"We will continue to expose, punish or close down websites that have a lot of vulgar content," said Cai Mingzhao, Vice Minister of the State Council Information Office, at a conference addressing the campaign.

The action to reduce harmful Internet content was hailed by the public. "I feel I'm obligated to report violators to the authorities and I want to be a volunteer Internet supervisor," said a university student in his open letter to the China Internet Illegal Information Reporting Center (CIIRC).

Chen Tong, Editor in Chief at Sina.com, said there was no point in being surprised about the crackdown. "Ensuring that your content is okay is a content provider's responsibility in the first place," he said