2007 | Marion Jones admits to doping, gets stripped of medalsAfter winning five gold medals at the 2000 Sydney Olympics and becoming a beloved American sports star, sprinter Marion Jones tearfully admitted (pictured) in October 2007 to using performance-enhancing drugs. In 2008, she spent six months in jail for perjury after admitting she lied to a grand jury that was investigating athletes suspected of doping. Photo: Stephen Chernin, Getty Images / 2007 Getty Images