The laughs are reportedly over for five top members of the hacker group LulzSec who were arrested on Tuesday and charged as part of a conspiracy case filed in New York federal court. FoxNews.com reports that the arrests were part of a multinational sting across the United Kingdom, Ireland and the United States on Tuesday morning, and LulzSec leader Hector Xavier Monsegur, who operated online under the alias “Sabu,” provided the Federal Bureau of Investigation with information leading to the arrests. According to the report, Monsegur has been working with the FBI for months. “This is devastating to the organization,” an FBI official told FoxNews.com. “We’re chopping off the head of LulzSec.” Read on for more.

LulzSec, which became part of the larger hacker collective “Anonymous Operations” last year, has launched a number of high profile cyberattacks since last summer. The group’s first widely reports attacks targeted a number of digital properties belonging to Sony, and more than 1 million accounts were compromised as a result of the group’s efforts.

The group also waged war on the U.S. government, and encouraged other hackers to “open fire on any government or agency that crosses their path.” This brazen move may have intensified the FBI’s efforts to take down the organization, as a series of arrests were made soon after operation “AntiSec” began.

LulzSec leader Hector Monsegur reportedly pleaded guilty to a dozen hacking-related charges on August 15th last year, and his ensuing cooperation with the FBI’s investigation will likely earn him a reduced sentence. “They caught him and he was secretly arrested and now works for the FBI,” a unnamed source said to be close to Sabu told FoxNews.com.

The five men arrested on Tuesday as a result of Monsegur’s cooperation include Ryan Ackroyd, aka “Kayla” and Jake Davis, aka “Topiary,” of London, England; Darren Martyn, aka “pwnsauce” and Donncha O’Cearrbhail, aka “palladium,” of Ireland; and Jeremy Hammond aka “Anarchaos,” of Chicago, Illinois. Further details are expected to be released later in the day.

UPDATE: FoxNews.com has published a follow-up piece that takes a closer look at Monsegur and further details his alleged cooperation with the FBI.