Swedish investigators are probing a hacker U.S. authorities accuse of unlawfully intruding into Cisco Systems, NASA’s Ames Research Center and NASA’s Advanced Supercomputing Division, the authorities said Monday. Philip Gabriel Pettersson, known in the hacking world as “ Stakkato ,” allegedly seized computer code that controls internet traffic. After the 2004 breach of Cisco, the proprietary source code for Cisco’s...