Chinese Army Unit Is Seen as Tied to Hacking Against U.S.
A New York Times article describing a cyber espionage unit, allegedly affiliated with the Chinese Army, that has made significant efforts towards infiltrating the computer networks of anything in the US that can be penetrated. The article is apparently based on a report released by Mandiant Corporation (PDF).
The New York Times article does not draw a direct line between the Chinese government and the South Carolina Department of Revenue hacking incident, but you do the math and see what you get.