"He was arrested on suspicion of conspiracy to commit unauthorised access to computer material contrary to Section 1 Computer Misuse Act 1990, conspiracy to commit unauthorised access with intent to commit further offences contrary to Section 2 Computer Misuse Act 1990; and conspiracy to commit unauthorised acts with intent to impair, or with recklessness as to impairing operation of a computer contrary to Section 3 Computer Misuse Act 1990."
For several months, a group calling itself "Crackas with Attitude" has been revealing information about Brennan as well as Jeh Johnson, the Homeland Security Secretary, James Clapper, the director of National Intelligence and FBI director Mark Giuliano.
WikiLeaks, the anti-secrecy group, began releasing documents from Mr Brennan's private AOL account in October, days after a hacker claimed he had gained access to it.
Other documents released so far have included a contact list, policy recommendations on Afghanistan and Pakistan, and his family's addresses and phone numbers.
Although an embarrassment, the documents have not exposed national security secrets, and Mr Brennan appears to have stopped using the account in 2008 when he rejoined the government after a period away from public life.
"I was certainly outraged by it," Brennan said of the hack at the time, adding that he also was troubled by the way some of the media handled it.
"Because of some things that were put out, the implication of the reporting was that I was doing something wrong or inappropriate or in violation of my security responsibility, which was not certainly the case," he said.
Meanwhile earlier this week, an anonymous hacker leaked sensitive data from over 20,000 supposed FBI employees and over 9,000 alleged Department of Homeland Security staff.
The cyber criminal carried out one half of the hack right after the Super Bowl kick off on Sunday night.
The hacker published a list of 9,000 DHS employees and on Monday he sent this message attached to the dump: "Long Live Palestine, Long Live Gaza" along with the hashtag "#FreePalestine", with the rest of the hacked information.
-Daily Mail