Hacktivist group Anonymous was at it again Thursday, claiming it had breached the servers of the North Atlantic Treaty Organization (NATO), but that it likely would not reveal most of the 1 gigabyte of information it said was stolen.

"Yes, #NATO was breached. And we have lots of restricted material," the group tweeted on its AnonymousIRC Twitter feed, one of several it and another hacker group, AntiSec, use to release information and news about their activities.

AntiSec includes members of Anonymous and LulzSec, another hacktivist group that officially ceased operations at the end of June.

Anonymous said it could not post most of the data because it would be "irresponsible," but still mocked the global treaty organization in another Twitter post.

"Hi NATO. Yes we haz [sic] more of your delicious data," the group tweeted. "You wonder where from? No hints, your turn. You call it war; we laugh at your battleships."

To prove its claim, Anonymous posted a link to a restricted-accessed NATO file on a PDF-sharing site.

Later via Twitter, it posted a link to another, non-restricted file the group said it lifted from NATO's servers, this one that outlines NATO security procedures.

Calling the file "ironic," Anonymous sarcastically tweeted that "Well, seems nobody ever read them."

The group said it used simple injection to infiltrate NATO servers, which typically means inputting bad code into Web forms to see if a backend database will react to the code.

NATO could not immediately be reached for comment Thursday. However, a published report claims the organization is investigating Anonymous' claims.

Anonymous and LulzSec Thursday also released a joint statement to the FBI, specifically addressing comments made in the press by FBI director Steve Chabinsky about the agency's efforts to fight the group's activities. The FBI on Wednesday said it arrested 16 people affiliated with Anonymous.

The groups in their statement reinforced their mission to target world governments with their attacks.

"These governments and corporations are our enemy." they said. "And we will continue to fight them, with all methods we have at our disposal, and that certainly includes breaking into their websites and exposing their lies."

Together, the groups have been unusually active over the last month and a half. Until it ended activity, LulzSec embarked on a 50-day hacking spree, targets of which included the Navy, the Arizona Department of Public Safety, and the CIA

Following LulzSec's self-enforced demise, AntiSec picked up where the latter left off in an international hacking spree as part of an "Operation Anti Security" campaign targeting government corruption around the world. Just about a week ago, AntiSec targeted federal contractor Booz Allen Hamilton and posted 90,000 military email addresses and passwords from the company online.

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