In the days after the Arleigh Burke-class guided missile destroyer USS John S. McCain collided with a Liberian-flagged oil and chemical tanker off near the Strait of Malacca on Aug 21., Chief of Naval Operations Adm. John Richardson sought to throw cold water on an alarming theory on the McCain collision smoldering among the amateur national security experts dwelling in the Internet’s fever swamps: Could a single cyberattack have compromised the $1.8 billion destroyer’s systems and disabled the warship without firing a single shot?