Technolog on msnbc.com (click for full article) "The vigilante group known as Anonymous has claimed credit for yet another of its weekly cyber attacks, fueling high level concerns among U.S. national security officials that the so-called "hackivists" are posing an increasing threat to government and private sector websites and computer systems. "What we've seen from Anonymous is alarming," Michael Leiter, the former director of the National Counter-Terrorism Center and a member of a US. Government advisory board on cybersecurity, said in an interview. "Their ability to repeatedly take down government websites and potentially penetrate those websites shows that the group is quite committed - and growing in its ability to perpetrate cyber attacks." In keeping with its pledge to launch cyber attacks every Friday, hackers associated with Anonymous today took credit for defacing a website associated with InfraGard, an organization that partners with the FBI to share information about potential cybersecurity threats. "We broke into their webserver, perused their assorted presentation materials, and finally deleted everything and vandalized their website," according to a statement posted on the Ohio chapter of InfraGard. The group describes itself as an association of businesses, academic institutions and law enforcement agencies that shares intelligence "to prevent hostile acts against the United States." The hackers in their statement called InfraGard a "sinister alliance between law enforcement, corporations, and white hat wannabees." (InfraGard did not immediately respond to a request for comment Friday.) The attack is the latest in a series of weekly strikes that appear to have confounded U.S. cyber security officials and prompted an ever expanding probe by the FBI. These have included temporarily shutting down the CIA's public web site, penetrating a transatlantic FBI conference call with Scotland Yard about ongoing investigations into hackers, taking down the Federal Trade Commission's website and penetrating the computers of a Washingto area law firm and dumping thousands of its private emails - including some with members of Congress onto the Internet."