Part of the cover of an issue from 2010
Did you know that al-Qaeda has an online magazine called 'Inspire'?
It's an English-language publication designed to spread al-Qaeda's message, as well as offering step-by-step instructions for creating weapons and carrying out attacks.
Last month, U.S. intelligence operatives managed to sabotage the publication of the latest edition.
On May 14, the eleventh issue of the magazine was published online, but text on the second page was garbled, and the next 20 pages were blank, the Washington Post reports.
The disruption didn't last too long: the damaged version of the magazine was quickly taken down, and a new, restored version went up on May 30.
According to an intelligence official, 'Inspire' is a threat because it "has a specific readership - a following. People will look for it, as opposed to something randomly posted."
The official also told the Post "it is very user-friendly. 'Inspire' uses pictures and step-by-step diagrams, and that's a problem."
Issue 11 praises the Boston Marathon bombing and warns of further lone-wolf attacks to come. An earlier issue offered step-by-step instructions on how to build a pressure-cooker bomb.
Dzhokhar Tsarnaev, one of the suspects in the bombing, told the FBI that he and his brother Tamerlan Tsarnaev learned how to make the pressure-cooker bombs they used in the attack from 'Inspire'.
Undated file photos of Tamerlan Tsarnaev and Dzhokhar Tsarnaev (Photos: AP)
That confession caused a debate within President Obama's administration about whether to disrupt the publication of 'Inspire'.
"There's a robust debate in the community about where do you draw the line on whether or not you should interfere with or take down certain sites," a second official said.
Adam B. Schiff, a member of the House Intelligence Committee says "I don't think al-Qaeda has a First Amendment right to put out its propaganda, to encourage people to commit acts of terrorism."
Another unnamed former official says "It's obvious if people are calling for crazies to murder a U.S. citizen, why wouldn't you stop it?"
But others argue that authorities should shift their target if they want to effect real change.
"The only way you're really going to be effective is to help amplify more mainstream moderate Muslim voices," said Michael E. Leiter, former director of the U.S. National Counterterrorism Centre. "That's vastly more effective than trying to disrupt radical voices."
As for how the magazine is disrupted, U.S. intelligence operatives apparently monitor the production of 'Inspire' through overseas computer networks and look for signs al-Qaeda is about to put out a new issue.
If authorities believe there's an imminent terror threat that could be increased by allowing the magazine to go online, they might disrupt publication.
Despite those efforts, though, the magazine's content usually ends up online in the long run, as it did in the case of Issue 11.
This isn't the first time intelligence agencies have taken aim at 'Inspire'.
In 2011, British agents with MI6 and GCHQ hacked into the magazine, and replaced bomb-making instructions with cupcake recipes.
When people tried to download the issue, which included an article titled "Make a Bomb in the Kitchen of Your Mom," they instead got a page of recipes for "The Best Cupcakes in America."