Anti-virus software veteran John McAfee argues that a spam email could take down the digital world. In a post on The International Business Times, McAfee points out that email lists are publicly available for most government agencies and corporations and at the same time, most people can't identify a spam email. He proposes that a spammer could hit the DOJ's 123,000 employees and steal about 55,000 logins. This access could then be used to shut down internal systems.