Head of Pentagon's Cyber Command Calls for Clear Cyber Security Legislation. US Army General Keith Alexander, head of the Pentagon's Cyber Command and the National Security Agency (NSA), has called for legislators to clarify who is responsible for what in defending the country's computer systems from attacks. General Alexander says it's important that the issues get sorted out before the US is the target of a major cyber attack. He pointed to the SANS 20 top controls as a model standard for what organizations need to do to protect their systems. Responsibility for defending the country's computer systems falls to several government agencies, including the Department of Defense, the FBI, and the Department of Homeland Security. General Alexander said, "The probability for crisis is mounting."