Who watches the watchers? The intelligence community itself, apparently — and it’s preparing for the next big whistleblower. Since Edward Snowden’s 2013 leak revealed that the NSA was spying on millions of Americans, U.S. intelligence agencies have increased their vigilance against insider threats. When some of the NSA’s cybertools turned up online this summer, many in Washington blamed a Russian hack. But the National Counterintelligence and Security Center is investigating a leak that might point to another rogue employee — and they’re monitoring their own ever more carefully.