The National Security Agency (NSA) is claiming a dozen groups connected to China's People's Liberation Army and six nonmilitary groups connected to universities are largely behind cyber spying campaigns. U.S. officials held meetings two weeks ago with Chinese counterparts and issued warnings about the diplomatic consequences of economic spying, according to the Wall Street Journal. James Lewis, a cyber security specialist at the Center for Strategic and International Studies, is quoted as saying that by combining cyber forensics with its own spying efforts the NSA has identified several individuals working within these groups. U.S. intelligence officials identified the groups tracing the type of cyber attack software they use, the various internet addresses used when absconding with data, and how the attack strategies are launched against different targets. All told, around 20 groups employing hundreds of people are responsible for the majority of the cyber theft of U.S. secrets, said people briefed on the investigation.