Today, 21 October 2015 and over the coming days WikiLeaks is releasing documents from one of CIA chief John Brennan's non-government email accounts. Brennan used the account occasionally for several intelligence related projects.
John Brennan became the Director of the Central Intelligence Agency in March 2013, replacing General David Petraeus who was forced to step down after becoming embroiled in a classified information mishandling scandal. Brennan was made Assistant to the President for Homeland Security and Counterterrorism on the commencement of the Obama presidency in 2009--a position he held until taking up his role as CIA chief.
According to the CIA Brennan previously worked for the agency for a 25 year stretch, from 1980 to 2005.
Brennan went private in 2005-2008, founding an intelligence and analysis firm The Analysis Corp (TAC). In 2008 Brennan became a donor to Obama. The same year TAC, led by Brennan, became a security advisor to the Obama campaign and later that year to the Obama-Biden Transition Project. It is during this period many of the Obama administration's key strategic policies to China, Iran and "Af-Pak" were formulated. When Obama and Biden entered into power, Brennan was lifted up on high, resulting in his subsequent high-level national security appointments.