March 27, 2012 at 1:24 PM ET
A group calling itself LulzSec Reborn is claiming credit for the hack of nearly 171,000 email addresses of those using the military dating website, MilitarySingles.com.
Under the heading of "#LulzSecReborn," the group said on a file-sharing site it obtained MilitarySingles.com emails with address locators such as "@us.army.mil ; @carney.navy.mil ; @greatlakes.cnet.navy.mil ; @microsoft.com ; etc."
The dating website "for single solders" and "those interested in meeting them" is not affiliated with the military.
Earlier this month, six suspected leaders of the Anonymous hacking group and its arm, LulzSec, were arrested and charged by U.S. authorities of computer crimes. Two of those arrested were from the U.S., including Hector Xavier Monsegur, known as "Sabu," and considered the de facto leader of LulzSec, who had been cooperating with the FBI investigation for months.
LulzSec and Anonymous previous took credit for a number of hacks and distributed denial-of-service attacks that shut down various government and private websites, including the CIA, the U.S. Senate website, Britain's Serious Organized Crime Agency and Sony.
The actions against those in the military or associated with it are not a first.
Last year, Anonymous infiltrated a server belonging to military consulting firm Booz Allen Hamilton and made available approximately 90,000 military email addresses online.
And just last month, Anonymous posted 3 gigabytes' worth of email correspondence by attorneys involved in the case of U.S. Marine Frank Wuterich, who pleaded guilty to killing two dozen unarmed Iraqi women and children in 2005. Wuterich's sentence — a demotion, rather than prison time — was the reason for the "revenge" by the group, which also hacked the website of Wuterich's attorneys.
In the latest attack, "email addresses, usernames, real names and -- in some cases -- physical addresses belonging to romance-seeking members of the military were included in the haul of information posted on the Internet," wrote Graham Cluley, senior technology consultant at security firm Sophos, on the company's blog.
"If you know anyone who has ever used the Military Singles website, it would be a good idea to tell them to change their password as a precaution -- and to ensure that they are not using the same password anywhere else," he said.
Msnbc.com has asked ESingles Inc., which runs the site and some others, for comment, and will update the post when we hear back.