Most people know the Chinese government restricts discourse on the Internet. But few people know Western companies help in the censorship process.

In China, public security forces and state-regulated service providers monitor every Internet posting and delete material considered objectionable by the communist government. Political content is the primary focus.

Now, U.S. companies are providing equipment and software that enables service providers to enter thousands of banned keywords and web addresses for automatic blocking.

Cisco Systems Inc., which is based in San Jose, Calif., sold the communist country routers that have the ability to block not only the main addresses for web sites, but also specific sub-pages, while leaving the rest of the site accessible.

So, Chinese censors can allow the country's 100-million odd Internet users to access most areas of Stanford University's web site, for example, while blocking a page for followers of Falun Gong, a group that's banned in China.

The same capability allows access to Google's main search page while blocking specific search results.

Human rights groups want to hold Western companies responsible for facilitating restrictive government policies. However, the companies insist that by connecting China to the World Wide Web, they've done more to encourage freedom in the country than restrict it.

Still, Reporters Without Borders estimates there are 75 cyber dissidents imprisoned worldwide, 63 of whom are in China.

"Whenever the Chinese government doesn't agree with the way something is happening, it finds a way to jump on in, and really put all its money and efforts and policing toward stopping it," says Tanya Churchmuch, president of Reporters Without Borders Canada.

Meanwhile, China continues to tighten its grip on Internet traffic. All web sites and web logs (blogs) had to be registered with the government by the end of June, and next comes an upgrade to its Internet infrastructure.

Over the next 12 months, new routers will be installed in 200 cities throughout China. Experts predict the new, improved network will enable the Chinese government to control and monitor online speech even more tightly.

The project offers ample opportunity for Cisco and Juniper Networks and France's Alcatel.