On the streets of Chinese cities, Big Brother has gone increasingly high-tech. Once, members of local Party committees essentially monitored their neighbors, sometimes filing reports on potential unrest and picking out future troublemakers. Today, some of that variety of Party watchdog still exists. But in cities like Lhasa, capital of the Tibet Autonomous Region, and historically a center of protest, cameras have replaced people, making it even tougher for activists to evade the police. In Lhasa, cameras mounted on buildings, poles, and stores watch the square in front of the Jokhang, Lhasa's holy temple.

Lhasa could prove a model for the country. Across China, local authorities are building camera surveillance in Internet cafes, city streets, and many other places, and Beijing has deployed what one comprehensive study called "the most extensive, technologically sophisticated, and broad-reaching system of Internet filtering in the world."--a system that blocks websites on certain topics and containing certain words. In Shenzhen, a prosperous city in southern China, local police are rolling out a kind of trial run, a massive camera system, placed on roadside poles, to watch Chinese citizens.

Last week, some congresspeople exploded after The New York Timesrevealed that American companies, and American investors, were helping build China's high-tech Big Brother. (Of course, other cities, like London, also operate camera systems, but there are fewer concerns that London police would use cameras to arrest peaceful demonstrators.) Turns out China Security and Surveillance Technology, a firm that helps install and operate surveillance systems for the Chinese police, has been allowed to list on the New York Stock Exchange. A similar firm, China Public Security Technology, also has incorporated in America, and the Times reported that American hedge funds have invested some $150 million overall in Chinese surveillance companies. Vowing action, California congressman Tom Lantos, a long-time human rights advocate, told the Times that this was "an absolutely incredible phenomenon of extreme corporate irresponsibility."

But anyone shocked to hear that a Chinese surveillance company was raising capital in America just hasn't been paying attention. For years now, not only have big American Internet companies contributed to Internet censorship; smaller, lesser-known foreign firms have provided the technology that helped China, Saudi Arabia, and other authoritarian governments crack down on online dissent.

Only a few examples of American firms' assistance have received much attention. Like other search engines operating in China, Google has agreed to filter out websites Beijing does not approve, like ones criticizing the Communist Party, discussing the 1989 Tiananmen crackdown, or featuring prominent figures critical of China like the Dalai Lama.

But others have gone much farther. Far worse, Yahoo reportedly gave the Chinese government personal information that may have been used to arrest Shi Tao, a leading Chinese journalist and activist. An Open Net Initiative study of Internet filtering suggests that Cisco Systems may have designed and developed a specific firewall for China. It's not only in China. The New York Times reported that foreign companies like Websense had competed to sell filtering technology to Saudi Arabia, also one of the most censored Internet systems in the world. The Saudis filter not only pornography and Israel-related sites but also sites of political opponents.

Several years ago, another comprehensive report by a leading Canadian human rights organization showed how, in November 2000, some 300 companies from sixteen countries attended a trade show in Beijing that helped lay the groundwork for "Golden Shield," a proposed Chinese nationwide surveillance and Internet censorship network. After the trade show, which featured Cisco, Motorola, Siemens, and many others, Canada's Nortel Networks helped China develop new surveillance technology, upgrade the ability of its Internet service providers to follow individual users, and develop better voice and face recognition technology. Other foreign firms reportedly helped China build a national database of information about all Chinese citizens.

Some foreign companies claim they are merely acceding to local laws and sensitivities. After all, they would do so in any other country, whether France or Thailand, where the Thai government blocked YouTube in order to prevent the distribution of footage supposedly critical of Thailand's revered king.

But the stakes are much higher in closed societies like Saudi Arabia or China. In those countries, Internet-based phone services and chat services have become almost the only secure ways for activists to communicate with each other and with the outside world. When I recently traveled in China to report on property-rights issues, I found that regular cell phone calls, not made with Internet phone services, were routinely tapped and intercepted, and authorities use these intercepts to find and detain activists. Besides Shi Tao, the Chinese government has jailed many other people for postings on the Internet. People like Guo Qizhen, one of the country's most famous Internet journalists, arrested for posting comments criticizing the Communist Party on two websites. When Guo's wife visited him in jail in June, she reportedly found him covered in bruises.

What's more, with China's human rights movements scattered and atomized, and without any one central leader, the Internet also has become the most vital forum in China for exchanging on topics ranging from property rights to how to sue the government. As a result, Chinese activists have told me, blocks on sites make it harder for them to share stories about how to fight for land rights, or how to organize petitions against the government

Congress will need to scrutinize the sale of surveillance technology, and it already is investigating Yahoo. Even better, as Council on Foreign Relations scholars Michael Levi and Elizabeth Economy suggest, before allowing IT companies to list in America, the Securities and Exchange Commission could force the firms to explain how they handle issues of censorship, surveillance, and Internet transparency. Of course, when the FBI today has demanded personal data from American Internet service providers without warrants, and the administration supposedly has launched massive searches of electronic databases containing e-mail and phone records, Washington doesn't have much moral high ground to stand on.

By Joshua Kurlantzick