The U.S. government has determined that North Korea was "centrally involved" in the cyber attack on Sony Pictures. The U.S. penetrated North Korean computer networks to trace the source of the hacking. According to investigators, the primary suspects are members of a North Korean cyber-security unit called "Bureau 121." However, it has not been ruled out that it is an insider at Sony with a grudge that cooperated with an outside group like the North Koreans. The White House is debating whether to publicly accuse North Korea of launching a cyberterrorism campaign against Sony. According to the New York Times, four years ago the NSA tried to infiltrate the country’s elite cyberteam to monitor malware, but the system is not foolproof as a lot of the hacking is done from China. This time, the hacking was done from centers across the globe, but one of the centers, in Bolivia, was the same used in the attack on South Korea.