The label XXX is usually plastered on adult magazines, naughty DVDs and signs for strip clubs. This year, XXX will have a new home, as a Web domain on your computer’s address bar. Think www.porn.xxx, www.naked.xxx or www.sex.xxx.

On Friday in San Francisco, the California nonprofit that oversees Internet addresses gave the green light to the virtual red-light district. The vote comes after several years of clashes and deliberations by the Internet Corp. for Assigned Names and Numbers.

Adult-entertainment sites will still populate the .com space and every other corner of the Internet. But now, many pornographic sites can also join a specialized domain that instantly telegraphs its content with the infamous suffix. ICM Registry, a Florida-based company that will run .xxx, said the domain’s Web sites will be the Internet’s most trusted place for adult entertainment: ICM will monitor the sites to ensure that they prohibit spam, viruses and any other illegal behavior. And it says it will use some of the registration fees for an affiliated foundation to promote free speech and combat child pornography.

“At the moment, the consumer has no way of knowing who is operating to good standards or has viruses,” Stuart Lawley, ICM Registry’s chairman and chief executive, said in an interview. “This new domain allows webmasters to associate with best business practices.”

But the dirty domain has a slew of critics. The Obama administration and some foreign nations say the domain’s offensive material will only encourage oppressive regimes to block .xxx entirely. A Commerce Department spokeswoman said the administration neither supports nor objects to the domain’s actual content or merit.

“We are disappointed that ICANN ignored the clear advice of governments worldwide, including the U.S.,” said Lawrence Strickling, assistant Commerce secretary. “This decision goes against the global public interest, and it will open the door to more Internet blocking by governments and undermine the stability and security of the Internet.”

Another set of foes, oddly enough: major pornography industry players, who fear that .xxx will be easily vulnerable to governments’ censorship. They also are concerned about aggressive policing by ICM and worry that porn Web sites will be forced to pay thousands of dollars in registration fees to buy multiple .xxx addresses simply to protect their brands from cybersquatters.

“This is putting a red target on us,” said Diane Duke, executive director of the Free Speech Coalition, a trade association representing multiple adult-entertainment organizations including Hustler. “People who are pedophiles and child pornographers are not part of the adult-entertainment system. We have a code of ethics. We do a great job of creating an adults-only space.”

The fears about governments targeting .xxx might be well-founded.

A spokesman for the Embassy of Saudi Arabia, which already bans pornography, said in an interview that the country would “absolutely” shut off access to.xxx.

“This would actually make our life much easier. If you can say that only pornography goes into this portal, it’s much easier to block it,” Nail al-Jubeir, the spokesman, said. “Most of the problems we face in Saudia Arabia are that porn sites tend to be under various Web site names, and it’s a cat and mouse game, where the sites pop up under different domain names and new sites. When we find out, we block it. It’s an uphill battle.”

ICANN officials say they are not aware of any large government blocking any one of the generic domains such as .com, .net or .biz. “If blocking were to happen, it would be precedent-setting. Our goal is to make sure the Internet addresses work globally and consistently around the world,” said Kim Davies, ICANN’s manager of root services. “Knowing you could open your computer in one country and get to a Web site, and go to a different country, and type it again and get it — that’s what we want to make happen.”

Lawley, a British expatriate who sold an Internet company in the United Kingdom for more than $200 million in 2000, said his critics are unfairly blaming him for the potential censorship by other countries. When ICANN next year approves hundreds of new domain names — like .gay, .news, or .IBM — more countries are bound to engage in more blocking, he said.

“How many countries will block .cnn and .facebook? Iran might block .newspaper or .amnesty,” said Lawley, who lives in Palm Beach, Fla. “It’s not the domain that brings instability, but the actions of the oppressive countries.”

What’s more, each new Web site registration on .xxx will cost about $70, with $10 going to an ICM-affiliated nonprofit promoting “online responsibility” and thwarting child pornography, Lawley said.

Peter Dengate Thrush, ICANN board chairman, said in an interview that .xxx will not increase the volume of porn on the Internet. “All dot-xxx does is make [pornography] more accessible,” he said. “It will be easier for people to filter it.”

On Thursday, several porn industry players protested outside the San Francisco hotel where ICANN was holding its meetings. Many took to the microphone to face off with the ICANN board, a mix of government and technology professionals from around the world.

“My name is John Stagliano, and I’m the owner of Evil Angel Productions, Evil Angel Video,” he said. “There’s a very real threat to free speech and to my particular freedom simply because I want to create art in my own way.”

Allison Vivas, president of Pink Visual, said that the porn industry doesn’t need any more regulation and that ICM is promoting its foundation as a marketing ploy.

“How many of you know that for years the adult industry has provided 100 percent of the funding to the Association of Sites Advocating Child Protection, an organization [that] has been recognized by the U.S. Congress?” Vivas said. “We have some critics who purposely attempt to demonize us and disseminate false information. And I say this as a protective mother of two young daughters.”

Greg Dumas, who runs several .com porn sites and supports .xxx, said some of his peers who oppose the domain are not thinking about .xxx’s potential business solutions.

“They think it’s a threat to their business models,” he said. “But it’s not. The adult business has been down for awhile, because there’s a lot of free content. But I hope this kick-starts the business, and we get new eyeballs and we get people excited looking for new business models.”