A number of al Qaeda’s online jihadist forums have gone down for extended periods.

Al-Qaeda’s main Internet forums have been offline for more than a week in what experts say is the longest sustained outage of the Web sites since they began operating eight years ago.

No one has publicly asserted responsibility for disabling the sites, but the breadth and the duration of the outages have prompted some experts to conclude that the forums have been taken down in a cyberattack — launched perhaps by a government, a government-backed organization or a hackers’ group.

US Cyber Command denied to the WaPo that it–or other US government agencies–were responsible.

There is still some uncertainty about whether a cyberattack caused the recent outages, and skeptics note that some prominent al-Qaeda forums remain online. U.S. government agencies, including U.S. Cyber Command, had no role in the outages, according to officials who would speak about the issue only on the condition of anonymity.

Still, Will McCants, a former State Department

Whereas government sources CNN contacted (Barbara Starr, CNN’s resident DOD mouthpiece, is bylined) declined to comment.

No entity has claimed responsibility and U.S. officials contacted by CNN would not comment.

Ssort of.

A U.S. official said the United States has been aware of the al Qaeda websites being down and finds it “of interest to us.”

But the WaPo also describes our government using foreign government assistance in the past.

In the past, U.S. officials have also relied on diplomatic channels to dismantle extremist sites that are viewed as a threat to American personnel or interests, according to former U.S. officials familiar with the episodes.

The approach has worked in more than a dozen cases and in each instance was backed by at least the implicit threat of a cyberattack by the U.S. military if the Web site’s host country failed to act, the officials said. The countries that cooperated were in Europe, the Persian Gulf and the Pacific, they said.

“We’ve never had a country refuse us,” said James Cartwright, the former vice chairman of the Joint Chiefs of Staff, speaking at a U.S. China Economic and Security Review Commission hearing at George Mason University last week. “But if they did, then you can invoke the right of self-defense.”

It reports the sites in question are hosted in Malaysia, Costa Rica and Gaza.

Meanwhile, Will McCants suggests to CNN that the outage may be related to Spain’s arrest of alleged Al Qaeda propagandist Mudhar Hussein Almalki

Zelin speculated the outage could be tied to the recent arrest of Mudhar Hussein Almalki in Spain. Almalki maintained the Ansar al-Mujahidin Forum, according to a Spanish police document provided to CNN. The police document alleges Almalki ran the site and oversaw who could access it, spread information to jihadists and maintained private chat rooms to “carry out meetings with others to give out instructions,” according to a translation of the document.

[snip]

Spanish police allege Almalki was a “prominent member” of al Qaeda’s propaganda arm, “following the guidelines and instructions of the terrorist organization.”

And meanwhile, the NYPD is drumming up its own online al Qaeda fear by pointing to references to Manhattan in another forum.

U.S. law enforcement and counterterrorism officials are trying to figure out the significance of recent occurrences on websites believed to have close links to al Qaeda, including a graphic some fear could be an attack threat directed at New York City.

The graphic contained a picture of the Manhattan skyline superimposed with a Hollywood-style caption that says: “ALQAEDA – coming soon again in New York.”

[snip]

A spokesman for the FBI office in New York said the Joint Terrorism Task Force was investigating whether the posting was authentic, and determined that while every threat is taken seriously “there is no specific or credible threat to New York.”

New York Police Department chief spokesman Paul Browne said his officers were “investigating the origin and significance of the graphic … which appeared today on a few Arabic-language al Qaeda forums that remain online at the moment.”

Browne noted, however, that the graphic was posted in a section of the forum labeled “art and design”. Kohlmann said that this raised questions as to whether the messages really constituted a serious threat. “That’s not where an important threat would be posted,” Kohlmann said.

Call me crazy. But with the Sabu takedown, we saw the FBI manipulate hacking skills as well as engage in apparent fearmongering. We also know the FBI has, in the past, used online propagandists to try to capture (right wing) terrorists in stings. And we know FBI has bragged of its cyber-expertise of late.

Maybe Cyber Command was the wrong entity to ask about an American cyberattack on the jihadist fora?