Gary Webb is an investigative journalist who worked for the San Jose Mercury News. In August 1996, he wrote a series (named "Dark Alliance") of newspaper articles which exposed a drug ring operating in the Bay Area, and its connection to the CIA and the Iran-Contra Scandal. Because of this expose, a media campaign formed to discredit him, making him look like an extreme conspiracy theorist.
Webb lost his job at the SJ Mercury News, and now publishes his work on the internet, because the mainstream press won't. He later wrote a book titled Dark Alliance: The CIA, the Contras, and the Crack Cocaine Explosion.
Gary Webb was reported dead in December, 2004 of a self-inflicted gunshot wound to the head.
Sources:
http://www.fromthewilderness.com/free/ww3/121304_gary_webb.shtml