HO CHI MINH CITY, Vietnam – It’s a wildly popular website laden with unlicensed songs and Hollywood movies, a prime exhibit of the digital piracy that is strangling the music industry in Asia and eroding legitimate online sales around the world.

The free-to-download bonanza has pushed Vietnam’s Zing.vn into the ranks of the globe’s top 550 websites. But a few clicks inside the site reveal a surprising presence: the U.S. government, which maintains a bustling social media account there.

Washington is a vocal proponent of intellectual property rights in Vietnam, as it is around the world, and a site like Zing would be shut down in the United States. But with space for public diplomacy limited in Communist Vietnam, the American embassy uses its “Zingme” account to reach out to young people in Vietnam as it seeks to build closer ties with its former enemy.

The embassy’s presence shows just how mainstream the pirate sites have become in Vietnam, where the government does nothing to stop them from operating. But it also raises questions about whether Washington is legitimizing a renowned pirate site that record labels, singers and industry groups say ignores requests that it take down infringing material.

Coca-Cola and Samsung pulled their advertising from the site earlier this month because of piracy concerns after questions were raised by The Associated Press. The move challenged Zing’s business model and was praised by recording industry groups. Samsung said last week that it was also closing its Zingme account for the same reason.

The embassy said it recognizes that Zing is a concern for U.S. copyright interests, but it believes that contact with the website’s users could reduce traffic or infringing activity on it. The mission sometimes uses its Zingme page to post about copyright infringement.

The embassy’s statement noted that the site had removed, at its request, the link to infringing material that appears on other Zingme pages as a matter of course. It also noted its lack of options in a country where the Communist government controls the media, saying “there were few spaces for public discourse.”

But not everyone thinks engaging with Zing is the right thing to do.

“Here we are as an American company trying to set things right with one of the biggest pirates in Vietnam, but the U.S. embassy is essentially showing its support by being on its site,” said Mimi Nguyen, an American who has been trying fruitlessly for a year to get Zing to take down some 10,000 songs owned by her family’s business. “It is really sad to find out the embassy is using their platform.”

The Recording Industry Association of America, which praised the decision by Samsung and Coke to withdraw from Zing and has labeled Zing a “notorious” pirate site, said it was neither endorsing nor criticizing the embassy’s decision to stay on the site.

Neil Turkewitz, a senior vice president at the association, said he imagined that the embassy had tried to balance the ability to target a tech-savvy demographic with anti-piracy messages, against the appearance of a connection between the embassy and the site.

“My guess is that it wasn’t an easy decision,” he said.

The recording industry around the world is struggling to make money from online distribution models, and illegal downloading remains rampant. Artists and producers in much of Asia are feeling the pinch especially hard because governments have failed to pass or enforce anti-piracy laws. Licensed CDs, films and downloads can cost the equivalent of a day’s salary, making it even harder to wean people off pirated products.

In Vietnam, inaction by a government that sees no political upside in cracking down on what many see as a victimless crime has pushed the industry to the point of collapse. Zing is seen as the No. 1 enemy by those who speak out against its effective stranglehold over the country’s music industry.

“Zing is destroying the industry, and they know it,” said record producer Quoc Trung, who is leading a campaign against online piracy. “We need people to pay for music, not just click on it. It is now or never.”

Zing, which declined repeated requests for comment on this article and a previous one, has used free downloading to become the sixth-most-visited site in Vietnam. Around 15 percent of its visitors are from overseas. It is not the only infringing website in Vietnam by far, but it is the most visited.

Sites that offer pirated content alongside other Internet services like Zing exist elsewhere around the world and are among the most reprehensible, according to the Recording Industry Association of America.

“They want to appear as legitimate actors, and have functions unrelated to piracy, yet operate network services that include features that intentionally and effectively induce infringement,” it said in a letter to the U.S. Trade Representative in August. The letter asked the government to use all the tools at its disposal to ensure that Zing and others are not permitted to undermine legitimate online markets.

“These services deliberately gain market share by providing access to infringing materials, launching music services without any form of licensing, and have demonstrated continued resolve to engage in conduct based upon misappropriation,” the association’s letter said.

Many in the industry have no choice but to work with Zing even as it distributes their music and films for free. Not having your music on the site means getting an audience for live concerts, or attracting commercial sponsorship, is almost impossible, industry executives said. But a few are pushing back, among them established singer Le Quyen, who is suing Zing and eight other infringing websites.

“I’m sure that Zing is aware that what they do is wrong, but they are afraid that other singers will put pressure on them if I win the case,” she said before one of her near-weekly concerts at a venue owned by her husband here. “That’s why they keep avoiding my demands. Their tactic is to drag the case on until their opponent gets tired and gives up.”

For now, the sites are not taking down their unlicensed content because doing so would mean that users would flock to that of a rival, and new ones are cropping up all the time. Those offering unlimited downloads of Hollywood movies for a monthly subscription as low as $2 are amassing large audiences, and could be looking to leverage their popularity to become legitimate providers.

“In Vietnam, you build an audience first, and then you negotiate,” said Phung Tien Cong, a manager at MVCorp, which is trying to establish a pay-for-song business in collaboration with Zing, other websites and license holders.