Blogger News Network

Roughly a dozen Chinese government agencies employ thousands of Web censors, Internet cafe police and computers that constantly screen traffic for forbidden content and sources -- a barrier often called the Great Firewall of China. Type, say, "media censorship by China" into emails, chats or Web logs, and the messages never arrive.

Even with this extensive censorship, Chinese are getting vast amounts of information electronically that they never would have found a decade ago. The growth of the Internet in China -- to an estimated 111 million users -- was one reason the authorities, after a week's silence, ultimately had to acknowledge a disastrous toxic spill in a river late last year. But the government recently has redoubled its efforts to narrow the Net's reach on sensitive matters.

It has required all bloggers, or writers of Web logs, to register. At the end of last year 15 Internet writers were in jail in China, according to the Committee to Protect Journalists, a New York group. China also has gotten some U.S. Internet companies to limit the search results they provide or the discussions they host on their Chinese services. A tiny firm Mr. Xia set up to provide and maintain Freegate had to lobby computer-security companies such as Symantec Corp., of Cupertino, Calif., not to treat it as a virus.

In response to China's crackdown, and to restrictions in many Middle Eastern countries as well, a small army has been mustered to defeat them. "Hacktivists," they call themselves.

Bennett Haselton, a security consultant and former Microsoft programmer, has developed a system called the Circumventor. It connects volunteers around the world with Web users in China and the Middle East so they can use their hosts' personal computers to read forbidden sites.