The Obama administration will proceed with a Bush-era plan to use National Security Agency assistance in screening government computer traffic on private-sector networks, with AT&T as the likely test site, according to three current and former government officials. — “We absolutely intend to use the technical resources, the substantial ones, that NSA has. But . . . they will be guided, led and in a sense directed by the people we have at the Department of Homeland Security,” the department’s secretary, Janet Napolitano, told reporters in a discussion about cybersecurity efforts. … The program is the most controversial element of...