With the Super Bowl less than a week away, US Customs has shut down a new set of Internet domain names for sites that linked to live sports broadcasts on the Web. As usual, the underlying servers were not affected and many sites are already running at new, non-US-controlled addresses.

Readers began notifying us this afternoon that sites like ATDHE.net were down, replaced with a US government warning page instead. US Customs has been running Operation In Our Sites for months now, making crackdowns in waves against sites accused of copyright infringement and counterfeiting. Customs has not yet announced the newest round of takedowns, though sites like the popular Spanish Rojadirecta were hit.

The sites make it possible to view just about every sporting event live online, even exclusive pay-per-view events, and the US Congress has taken notice. In 2009, it held a hearing on "Piracy of Live Sports Broadcasting Over the Internet" at which law professor Christopher Yoo called out ADTHE by name (PDF).

Customs generally seizes the domain name by petitioning a federal judge. The seizure happens without notice or warning, though affected sites can go to court after the fact to challenge it. Customs doesn't attempt to actually shutter sites, since most of the servers in questions are located outside the US; instead, it simply seizes US domain names. The sites can be back online in minutes by simply switching their .com suffix to a .me—or to many other options.

Still, Customs is pleased with its results. John Morton, current head of the department, said last month at a DC conference that he'd been warned these modest Whac-A-Mole tactics wouldn't work. But surprisingly, he says they have.

And frankly unanticipated, was the collateral impact of this enforcement action. According to industry analysis, 81 other sites that had been offering pirated material voluntarily shut themselves down. In my many years in law enforcement, I have not seen that type of deterrence. Indeed, we were advised that seizing these domain names would be the proverbial Whac-a-Mole game with new ones popping up faster than we could obtain court orders. That did not occur and while two of the original domain names seized did reemerge in another form, the vast majority did not and two months ago, we seized one of the two that had been resurrected and was offering pirated movies again. It has not reemerged since.

Still, many of today's seizures are already back online. Rojadirecta and ADTHE have switched to .me suffixes, while Channelsurfing has switched to a Channelsurf.eu address. "www.channelsurfing.net was seized today by homeland security," said the site, while Rojadirecta's home page said, "US authorities 'steal' our domain rojadirecta.org and rojadirecta.com!"

Are the sites actually illegal? Many consist solely of links to other sites, which in turn link to other sites. TorrentFreak notes the curious case of Rojadirecta, which was sued in Spain by rightsholders but actually prevailed—twice. Still, Customs believes the sites break US law, and it's managed to convince a judge that there's enough evidence of wrongdoing to seize the domains. We'll know more when the actual affidavits are unveiled.