South Africa's Caster Semenya reacts after receiving her silver medal for the women's 800-meter during the athletics in the Olympic Stadium at the 2012 Summer Olympics, London, Saturday, Aug. 11, ... more 

South Africa's Caster Semenya reacts after receiving her silver medal for the women's 800-meter during the athletics in the Olympic Stadium at the 2012 Summer Olympics, London, Saturday, Aug. 11, 2012. (AP Photo/Matt Slocum) less