HANOI, Vietnam - When the entire e-mail system suddenly went dark throughout Vietnam, the government-owned agency that administers the Internet told its subscribers not to panic: The disruption was caused by routine maintenance on the country's fire wall.
Vietnam and other Asian governments have installed nationwide fire walls, or electronic filters, that keep Internet users from connecting to Web sites that the regimes consider politically, religiously or sexually offensive. But one of the principal custodians and censors of the Vietnamese fire wall now acknowledges his wall is overmatched and doomed.
"Control through the fire wall is no longer effective," said Do Quy Doan, chairman of the Vietnam Web Site Project at the Ministry of Culture and Information. "If anyone who has a wish to get over the wall, they will. It is just a technical measure. If we put all our future hopes on the fire wall, we will fail."
The admission from a senior technocrat does not mean it is curtains for Hanoi's Internet Iron Curtain. The ruling Communist Party here still takes many of its political and ideological lessons from China, and Beijing has recently reinforced its already draconian restrictions on Internet use. China uses its fire wall to block all manner of sites, including Western media outlets, human-rights organizations and the Falun Gong spiritual movement.
Other countries in Southeast Asia also are worried about the growing political reach and grasp of the Internet, particularly when it is used by opposition parties and activists.
Singapore, with a general election coming up, has announced it will impose new restrictions on political Web sites and chat forums. And Malaysia, which advertises itself as the most tech-friendly nation in Southeast Asia, is said to be drafting tough new revisions to its existing "cyber laws."
In Vietnam, the fire wall already blocks well over 3,000 Web sites - and those are just the pornographic ones.
Countless political and religious sites also get fire-walled, in addition to proxy servers and so-called back-door sites that usually can be used to leap tall fire walls in a single bound.
Doan declined to give statistics on the number of those sites deemed to be off-limits, although it is believed there are more than a thousand of them on Hanoi's blacklist.
"Of course we have those bad political sites, but those people can also get you their information through e-mail, fax, radio," Doan said. "Nobody can control all that."
The government clearly recognizes that its foreboding fire wall drives off potential foreign investors while hamstringing domestic entrepreneurs. Indeed, fire-wall-free office space is dangled as an inducement for businesses to relocate to Quang Trung Software City, a 92-acre corporate park in Ho Chi Minh City. Quang Trung is the only place in the country - other than the defense and public security ministries - that is legally beyond the fire wall.
Nguyen Anh Dung, 37, managing director of SSL Vietnam, said his company would simply not exist if not for the fire wall exemption inside the Quang Trung park. SSL Vietnam is developing a handheld computer called MineTerapin that it hopes to launch.
"When we had an office in the city, we had to go through the fire wall and that made the Internet so slow," Dung said. "If we were still in our old place, we couldn't do this project. It would be impossible."
There are countless anti-Hanoi political sites operating on the Web, of course, most of them run by refugees and emigres living outside Vietnam. These sites are routinely blocked from users inside Vietnam.
"Of course they block us, but it's not because of our content," said Pham Ngoc Lan, the Web master for Thong Luan, the online newsletter of the Rally for Pluralism and Democracy, a Vietnamese emigre group based in San Jose, Calif. "We're moderates who are simply talking politics, and that's enough for them to block us. The culture police read us."
There are five Internet service providers in Vietnam, all of them state companies that lease access to the country's sole gateway from a state-owned agency, the Vietnam Data Communications Co. Even with a population of 77 million, Vietnam has just 135,000 Internet subscribers, due largely to high sign-up costs and user fees.
Even with complaints from businesses and consumers and a losing technological battle, the Vietnamese authorities show no signs of tearing down their fire wall.
Doan said Hanoi would launch a "propaganda campaign" to educate and warn its citizens about the accessing of inappropriate sites. Also, new laws and decrees will make it illegal to connect to naughty sites, with large fines being the principal deterrent.