GOLDEN VALLEY, MINN. - David Petraeus blazed a trail as a four-star general. He is the man many credit for turning around the Iraq and Afghanistan wars. But the electronic trail he left behind cost him his career.
At the center of massive investigation is Paula Broadwell and the emails she exchanged with the retired general and his family friend Jill Kelley.
During the FBI probe more than 20,000 pages of potentially inappropriate emails were found between Kelley and General John Allen, NATO commander in Afghanistan.
The investigation has people wondering how the head of the CIA didn't know his private emails would become so public.
"Should he have known? Absolutely, I think he should have known," professor Jane Kirtley, who teaches media ethics and law at the University of Minnesota, said
Kirtley said always assume everything you do in the digital world, from home or work, is public.
"There's very little expectations of privacy in your sent emails...because they go through so many servers that there's really no way that you can guarantee that your communication will remain confidential," she said.
Petraeus and Broadwell thought their communication would be confidential.
In fact, the two shared a gmail account and would write each other messages and then save them in the "drafts" folder. That still didn't keep their affair a secret.
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