A sign for the National Security Agency, U.S Cyber Command and Central Security Service, is seen near the visitor’s entrance to the headquarters of the National Security Agency on February 14, 2018. (Photo by SAUL LOEB/AFP via Getty Images) Former top NSA cyber official: Probationary firings ‘devastating’ to cyber, national security Rob Joyce emphasized during a House hearing how important probationary employees are to NSA efforts to counter China and other threats in cyberspace. 12 hours ago By Derek B. Johnson