U.S. Fighting Chinese Hacking of Defense Contractors

As the White House moves to confront China over its theft of U.S. technology through hacking, policy makers are faced with the question of how much damage has already been done. During their multiyear assault on defense contractors, the spies stole several terabytes -- equal to hundreds of millions of pages -- of documents and data on weapons programs, dwarfing in sheer quantity any theft of Cold War secrets.