China hack: Chinese hackers gain access to over 1 million American cellphone records, sources say [Video]

U.S. officials suspect that a recently discovered Chinese hacking and espionage campaign scooped up data on hundreds of thousands of American mobile phone users, likely stealing information about more than 1 million customers, ABC News has learned.

Sources familiar with the investigation gave ABC News a detailed sense of the vast scope of what U.S. officials are calling a major intelligence-gathering operation by China, exploiting weaknesses in the communications networks of the nation’s top telecommunications companies.

In a briefing on Tuesday, FBI and Homeland Security’s cyber officials said that the Chinese were able to steal a “large amount of data” — officially acknowledging for the first time that China was able to determine who thousands of mobile phone users were talking to, when they spoke and where they were communicating from.

China initially appeared to have focused on a huge swath of mobile phone users in the national capital region. …