4. Tour de France Doping Allegations
Doping scandals at the Tour de France date back to the early 1900s, but it was in 1998 that the first major doping scandal erupted, complete with hotel-room raids by French police and a sit-down strike by riders on the 17th stage.
Stricter drug testing requirements followed, as well as the formation of the World Anti-Doping Agency.
Nonetheless, doping allegations remain a constant at the Tour de France, with seven-time former champion Lance Armstrong being a favorite target.
Despite relentless accusations, Armstrong has never been found guilty of using illegal performance enhancers, although several others have, including Jan Ullrich and Floyd Landis in 2006 and Alexander Vinokourov and Cristian Moreni in 2007.