It may be one of the world's most sophisticated games of cat and mouse. As governments become increasingly skilled at censoring and filtering the Internet, determined citizens are finding creative ways to access unfettered information online. Proxy servers have long been the tool of choice in that struggle. They allow users to route their Web surfing through masked, secure computer servers, usually located in Western countries. One of the most popular, Germany-based Anonymouse.org, gets more than 3 million users per day. But proxies have one major weakness: Once a government spots one, access can be blocked.
So online advocates have been forced to get creative. In 2004, employees of the U.S. Broadcasting Board of Governors, which is charged with finding ways to broadcast information into authoritarian countries, posed as players in the popular online game Lineage. The employees' characters provided details on available proxies -- until they were "beaten down by [virtual] thugs," says Kenneth Berman of the U.S. agency. The U.S. government and Net freedom activists have also experimented with text-message numbers that automatically send lists of proxies to mobile phones. Other efforts are more complex. One software program called Psiphon, which was developed by researchers at the University of Toronto's Citizen Lab, allows any person with a computer to serve as a proxy for someone living behind a firewall. Since it was launched a year ago, more than 100,000 people have turned their personal computers into proxies.
The most sophisticated proxy technology may be Tor, developed jointly by the U.S. Naval Research Laboratory and the Electronic Frontier Foundation, an Internet freedom advocacy organization. Tor is a downloadable software that routes an Internet surfing session through three proxy servers randomly chosen from a network of more than 1,000 servers run by volunteers worldwide. "Tor is state of the art," says John Mitchell, an expert on Internet security at Stanford University. For citizens of repressive regimes, it may be the best hope of evading the cat's paw.