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Political scientists at the University of Toronto have built another system, called Psiphon, that allows anyone to evade national Internet firewalls using a Web browser. Sensing a business opportunity, they created a company to profit by making it possible for media companies to deliver digital content to Web users behind national firewalls.
The Iranian government, more than almost any other, censors what its citizens can read online, using elaborate technology to block millions of Web sites offering news, commentary, videos, music and, until recently, Facebook and YouTube.
Search for “women” in Persian and you are told, “Dear Subscriber, access to this site is not possible.”
Last July, an escape hatch appeared on popular sites that offer free downloads of various software. The computer program allowed Iranian Internet users to evade government censorship.
College students discovered the key first, then spread it through e-mail messages and file sharing. By late autumn, more than 400,000 Iranians were surfing the uncensored Web.
The software was created not by Iranians, but by Chinese computer experts volunteering for Falun Gong, the spiritual movement suppressed by the Chinese government since 1999. They maintain a series of computers in data centers around the world to route Web users’ requests around censors’ firewalls.
The Internet is no longer just an essential channel for commerce, entertainment and information. It has also become the stage for state control — and rebellion against it. Computers are becoming more crucial in global conflicts, not only in spying and military action, but also in determining what information reaches people around the globe.
More than 20 countries now use increasingly sophisticated blocking and filtering systems for Internet content, according to Reporters Without Borders, a group based in Paris that encourages freedom of the press.
Although the most aggressive filtering systems have been erected by authoritarian governments like those in Iran, China, Pakistan, Saudi Arabia and Syria, some Western democracies are also beginning to filter some content, including child pornography and other sexually oriented material.
In response, a disparate alliance of political and religious activists, civil libertarians, Internet entrepreneurs, diplomats, and even military officers and intelligence agents are now challenging growing Internet censorship.
The creators of the software seized upon by Iranians are members of the Global Internet Freedom Consortium, based largely in the United States and closely affiliated with Falun Gong. The consortium is one of many small groups developing systems to make it possible for anyone to reach the open Internet. It is the modern equivalent of efforts by organizations like the Voice of America to reach the citizens of closed countries.
Separately, the Tor Project, a nonprofit group of anti- censorship activists, freely offers software that can be used to send messages secretly or to reach blocked Web sites. Their software, first developed at the U.S. Naval Research Laboratories, is used by more than 300,000 people globally, from the police to criminals, as well as diplomats and spies.
Political scientists at the University of Toronto have built another a system, called Psiphon, that allows anyone to evade national Internet firewalls using a Web browser. Sensing a business opportunity, they have created a company to profit by making it possible for media companies to deliver digital content to Web users behind national firewalls.
The danger in this quiet electronic war is driven home by a stark warning on the group’s Web site: “Bypassing censorship may violate law. Serious thought should be given to the risks involved and potential consequences.”
In this cat-and-mouse game, the cat is fighting back. The Chinese system, which opponents call the Great Firewall of China, is built in part with Western technology. A study published in February by Rebecca MacKinnon, who teaches journalism at the University of Hong Kong, determined that much blog censorship is performed not by the government but by private Internet companies like Yahoo China, Microsoft and MySpace. One-third to more than half of all postings made to three such sites were not published or were censored, she reported.
When the Falun Gong tried to support its service with advertising several years ago, U.S. companies backed out under pressure from the Chinese government, members said.
In addition, the Chinese government employs more than 40,000 people as censors at dozens of regional centers, and hundreds of thousands of students are paid to flood the Internet with government messages and crowd out dissent.
This is not to say that China blocks access to most Internet sites; most of the material on the global Internet is available to the Chinese without censorship. The government’s censors mostly censor groups deemed to be state enemies, like the Falun Gong, making it harder for them to reach potential members.
Those who back the ragtag opponents of censorship criticize the government-run systems as the digital equivalent of the Berlin Wall.
They also see the anti-censorship efforts as a powerful political lever.
“What is our leverage toward a country like a Iran? Very little,” said Michael Horowitz, a fellow at the Hudson Institute who advises the Global Internet Freedom Consortium.
The U.S. government and the Voice of America have financed some circumvention technology efforts. But, until now, the Falun Gong has devoted the most resources, experts said, erecting a system that allows the largest number of Internet users open, uncensored access.
Each week, Chinese Internet users receive 10 million e-mail messages and 70 million instant messages from the consortium, offering software to bypass the elaborate government system that blocks access to the Web sites of opposition groups like the Falun Gong.
Shiyu Zhou, a computer scientist, is a founder of the Falun Gong’s consortium. His cyberwar with China began in Tiananmen Square in 1989.
He said he first understood the power of government-controlled media when the nation’s student protesters were turned overnight from heroes to killers.
“I was so disappointed,” he said. “People believed the government; they didn’t believe us.”
He decided to leave China and study computer science in the United States. In the late 1990s, he turned to the study of Falun Gong and then joined a small group of technically sophisticated members of the spiritual group intent on transmitting millions of e- mail messages to Chinese. Both he and Peter Yuan Li, another early consortium volunteer, had attended Tsinghua University.
The risks of building circumvention tools became clear in April 2006, when, Mr. Li told law enforcement officials, four men invaded his home in suburban Atlanta, covered his head, beat him, searched his files and stole two laptops. The F.B.I., which has made no arrests in the case, would not comment. Mr. Li said he thought China had sent the invaders.
Early on, the group of dissidents had some financial backing from the International Broadcasting Bureau of the Voice of America for sending e-mail messages, but the group insists that most of its effort has been based on volunteer labor and contributions.
The consortium’s circumvention system works this way: Government censorship systems can block access to certain Internet protocol addresses. The equivalent of phone numbers, these addresses are quartets of numbers, like 184.108.40.206, that identify a Web site, in this case, google.com. By clicking on a link provided in the consortium’s e-mail message, someone in China or Iran trying to reach a forbidden Web site can download software that connects to a computer abroad that then redirects the request to the site’s forbidden address.
The technique works like a basketball bank shot — with the remote computer as the backboard and the desired Web site as the basket. But government systems hunt for and then shut off such alternative routes using a variety of increasingly sophisticated techniques. So the software keeps changing the Internet address of the remote computer — more than once a second. By the time the censors identify an address, the system has already changed it.
China acknowledges that it monitors Internet content, but it claims to have an agenda much like that of any other country: policing for harmful material, pornography, treasonous propaganda, criminal activity, fraud. The government says Falun Gong is a dangerous cult that has ruined the lives of thousands of people.
Hoping to step up its circumvention efforts, the Falun Gong organized extensive lobbying last year in the U.S. Congress, which approved $15 million for circumvention services.
But the money was awarded not to the Falun Gong consortium but to Internews, an international organization that supports local media groups.
This year, a broader coalition is organizing to push for more congressional financing of anti-filtering efforts. Negotiations are under way to bring together dissidents of Vietnam, Iran, the Uighur minority of China, Tibet, Myanmar, Cuba, Cambodia and Laos, as well as the Falun Gong, to lobby Congress.
Mr. Horowitz argues that $25 million could expand peak usage to 45 million daily Internet users, allowing the systems to reach 10 percent of the Web users in both China and Iran.
Mr. Zhou says his group’s financing is money well spent. “The entire battle over the Internet has boiled down to a battle over resources,” he said. “For every dollar we spend, China has to spend a hundred, maybe hundreds of dollars.”
As for the Falun Gong software, it proved a little too popular among Iranians. By the end of last year, the consortium’s computers were overwhelmed. On Jan. 1, the consortium had to do some blocking of its own: It shut down the service for all countries except China.