By Alexandra Berzon

A Brazilian court ordered YouTube to shut down Thursday after a sultry model sued to remove a sex video that had been posted on the popular video sharing Web site.

But does Brazil have the power to do that?

Companies, countries, and courts have grappled for control of the Internet since early geeks first exchanged electronic messages, but the struggle to regulate the Internet has only become more complex as Web giants such as Google and Yahoo continue to expand their reach around the world.

The latest debate was sparked when Daniella Cicarelli, a well-known model and ex-wife of superstar soccer player Ronaldo, sued YouTube after a video showing her having sex on the beach with her boyfriend appeared on the website and became the most-viewed video in Brazil, Reuters reported.

Ms. Cicarelli demanded the video be taken down and asked for $116,000 in damages for each day it remained up. A Brazilian judge ordered YouTube to be shut down until the video, which kept popping up over and over, was permanently removed from the site.

YouTube declined to comment on the case, but the Web site was, not surprisingly, still alive and well Thursday afternoon.

The case, however, cuts to the heart of questions over internet control.

“It’s a big concern for Internet companies,” said John Palfrey, a HarvardLawSchool professor and director of the school’s BerkmanCenter for Internet and Society. “If you’re a service based in the United States, does that mean you can be hauled into court in 200 other countries?”

Legal experts say YouTube would be covered in the U.S. under the Communications Decency Act, which protects companies against liability for content that’s posted by users. But in Brazil, such protection does not, apparently, exist.

“It’s perfectly legitimate for Brazil to do whatever it can to stop YouTube from showing the video,” said Jack Goldsmith, a Harvard Law School professor and author of “Who Controls the Internet? Illusions of a Borderless World.” “The state has the ability to regulate what’s in its borders.”

But then the issue becomes one of enforcement, say legal experts.

“The question for Brazil is, does the company have assets in the jurisdiction that they can seize?” said Mr. Palfrey. “Next time (Google founders) Larry (Page) or Sergey (Brin) fly to Rio, will they put handcuffs on them?”

That’s why, for example, Yahoo and Google may have been quick to comply last year with Chinese orders to censor their search engines, said Mr. Goldsmith.

Mr. Palfrey said he expects YouTube to bring the case to U.S. courts, which are likely to be friendlier. “My sense is that Google is a law-abiding company, and they’ll figure out how to fight a lawsuit against them and then comply if the judgment comes down against them,” said Mr. Palfrey. “I’d be surprised if U.S. companies started to defy foreign orders on a regular basis.”

But precedent for such cases remains murky. In 2000, a French judge ordered Yahoo to remove content and pay a $15 million fine for carrying an auction site containing Nazi memorabilia, which is banned in France. However, Yahoo was never forced to pay the fine and the issue of Internet company liability in foreign courts was never resolved.

Google and Brazil have been at odds before. A Brazilian court last year ordered Google to turn over information about users of its social networking site Orkut, which is immensely popular in Brazil. Google refused, arguing it did not have to turn over information stored in the company’s U.S. headquarters.

The United States has also found itself on the other side of the enforcement coin, as it tries to impose recently passed internet gambling prohibitions against foreign online gambling companies.

“With the reach of the internet, as it becomes more and more a part of every day life, that’s going to raise a lot of extraterritorial legal issues,” said attorney Martin Samson, who specializes in Internet law. “There are all sorts of countries, and all sorts of views about how the world should be run, and they’re not always the same.”

Contact the writer: aberzon@redherring.com