UPDATE 2-Naturalized U.S. citizen charged with being agent of China

A naturalized U.S. citizen working as a tour guide in the San Francisco area was charged on Monday with being an agent of the Chinese government, providing officials there with classified U.S. national security information.Xuehua Peng, also known as Edward Peng, was taken into custody on Friday in Hayward, California, and was denied bail during an initial court appearance before a U.S. magistrate judge that same day, federal prosecutors said at a Monday morning news conference."The conduct charg