Richard Forno, Cybersecurity, urges the Department of Defense to quickly move away from using Social Security numbers as unique identifiers due to data breaches. See articles:
Military's Use Of Social Security Numbers A Vulnerability For Veterans (Jefferson Public Radio)
Military's Use Of Social Security Numbers A Vulnerability For Veterans (KUOW)
Military's Use Of Social Security Numbers A Vulnerability For Veterans (WUNC 91.5)
Military's use of social security numbers a vulnerability for veterans (89.3 KPCC)