"I was certainly outraged by it," Brennan said Tuesday at an intelligence conference at George Washington University when asked about his reaction to learning of the hack.
"I certainly was concerned about what people might try to do with that information," Brennan added. "I was also dismayed at how some of the media handled it, and the inferences that were in there."
A self-proclaimed high school student said he hacked Brennan's email last week, and the document leak site Wikileaks published some of the contents of his email later in the week. Though none of the emails contained any classified information or appeared to come from his time at the agency, it did contain sensitive information including Social Security Numbers and passport numbers of his family.
But Brennan said the fact that his email was hacked is not a sign that he somehow neglected his job or is unfit.
"Although we are government officials, we also have family and friends, bills to pay, things to do in our daily lives, and the way you communicate these days is through the Internet," Brennan said. "The implication of some of the reporting was that I was doing something inappropriate or wrong or a violation of my security responsibilities -- which was certainly not the case."
Brennan said the whole incident is a case study in the power of ill-intentioned actors in a cyber-enhanced world.
And that's a central focus of his agency, he added.
"What it does is to underscore just how vulnerable people are to those who want to cause harm," he said. "We really have to evolve to deal with these new threats and challenges."
Deputy Director of the Defense Intelligence Agency Doug Wise, participating on the same panel as Brennan, said that the risk of being targeted is a burden the public faces of the intelligence community bear as part of their service.
"One of the risks of being a public intelligence figure is you make yourself a target," Wise said.