Chinese Official Claims Evidence of U.S. Hacking

China's top Internet security official says he has "mountains of data" pointing to extensive U.S. hacking aimed at China, but it would be irresponsible to blame Washington for such attacks, and called for greater cooperation to fight hacking. Cyber security is a major concern for the U.S. government and is expected to be at the top of the agenda when President Barack Obama meets with Chinese President Xi Jinping in California.