Shanghai, July 2 Under the controversial Green Dam computer program, China has already installed censorship software in over half-a-million computers.

According to a report in The Telegraph, the Green Dam program has been downloaded three million times since the end of March and has been installed on 518,000 computers. Almost 7,000 websites in China have also installed the software.

On Tuesday night, the Chinese ministry of Industry and Internet Technology issued a short statement, indefinitely delaying a plan to make Green Dam compulsory on all computers sold on the mainland. The regulation was due to come into force on Wednesday.

The government retreated from the plan after fierce opposition from computer manufacturers, the US government and Chinese Internet users.

Once Green Dam is installed on a home computer, it links to a central database and automatically filters out all pornography and some politically sensitive content.

A spokesman for the US embassy said they welcomed the decision by the government to shelve the project.

According to researchers at the University of Michigan, the installation of Green Dam leaves computers more vulnerable to hacking. It may also be able to report an individual's web-use back to the Chinese authorities.

A number of major computer manufacturers have already started selling computers with the software.

Sony and Lenovo, the Chinese company which bought IBM's PC division, have already sold Green Dam compliant machines, while Acer, the Taiwanese manufacturer, said yesterday it intended to comply with the regulation. (ANI)