The material presumably was taken in a compromise of Brennan's email account by a hacker who told The New York Post he is a high school student protesting American foreign policy. The hacker claimed he posed as a Verizon employee and tricked another employee into revealing Brennan's personal information.
Brennan was seeking a security clearance while applying for a job as White House counterterrorism adviser. It was not immediately clear whether any national security information was compromised in the release of the clearance application, which includes his wife's Social Security number and the names of people Brennan worked with over a long prior career at the CIA.
A CIA statement called the postings a "crime."
"The Brennan family is the victim," the agency said in an unattributed statement, in keeping with agency policy. "This attack is something that could happen to anyone and should be condemned, not promoted. There is no indication that any the documents released thus far are classified. In fact, they appear to be documents that a private citizen with national security interests and expertise would be expected to possess."
The documents all date from before 2009, when Brennan joined the White House staff; before that, he was working in the private sector. Aside from the partially completed clearance application, none of the documents appears to be sensitive.
In a section of his security clearance application covering foreign contacts, Brennan writes that in August 2007: "I have had lunch twice and dinner once with Alan Lovell, a UK colleague with whom I worked closely during the last three years of my government career. Alan is currently posted at the UK Embassy in Washington."
Brennan's "government career" to that point consisted of decades at the CIA. It's not clear what Lovell's role was at the British Embassy. The State Department in 2009 listed Lovell as a "counselor" in the British Embassy. His LinkedIn profile currently lists him as working at the British Ministry of Defense.
The documents include a partially written position paper on the future of intelligence, a memo on Iran, a paper from a Republican lawmaker on CIA interrogations and a summary of a contract dispute between the CIA and Brennan's private company, the Analysis Corporation, which had filed a formal protest after losing a contract dealing with terrorist watch lists.
In a post-election memo, purportedly written to Obama, Brennan laid out a pragmatic roadmap on dealings with Iran. His suggestions are similar to the carrot-and-stick approach the administration would eventually use in nudging Tehran toward joining negotiations over slowing the momentum of its growing nuclear reactor program.
"The United States has no choice but to find ways to coexist - and to come to terms - with whatever government holds power in Tehran," Brennan said in the three-page memo. He added that Iran would have to "come to terms" with the US and that "Tehran's ability to advance its political and economic interests rests on a non-hostile relationship with the United States and the West."
In the memo, Brennan advised Obama to "tone down" rhetoric with Iran, and swiped at former President George W. Bush for his "gratuitous" labeling of Iran as part of a worldwide "axis of evil." Brennan also said the US should establish a direct dialogue with Tehran and "seek realistic, measurable steps." Although he didn't specifically call for the regime of financial sanctions that the Obama administration, along with Europe, Russia and China, pushed against Iran, Brennan told the president-elect to "hold out meaningful carrots as well as sticks."