Rio 2016: 'Hands off Caster' trends in South Africa

More than 17,000 tweets made the hashtag #HandsOffCaster South Africa's top trend over the past weekend. It sent a clear message - South Africans were ready to defend their middle-distance runner Caster Semenya from persistent questions over whether she should be excluded from racing in Rio.

Semenya was made to undergo gender testing after winning gold at the 2009 World Championships in Berlin. She was cleared to compete in 2010 after being sidelined for 11 months while the tests were carried out.

The tag #HandsOffCaster appears to date back to the London 2012 Olympics, but again began to trend over the weekend, following the publication of two magazine articles in the US. The title of the Sports Illustrated piece was, "Is it fair for Caster Semenya to compete against women at Rio?" The second article was a conversation between author Malcolm Gladwell and editor Nicholas Thompson for the New Yorker.

When Thompson asked whether Semenya should be allowed to race with other women, Gladwell responded "of course not... Remember, this is a competitive issue, not a human-rights issue."

Gladwell, who is a proponent of the 10,000-hour rule (the theory that it takes 10,000 hours of practice to achieve mastery of a skill), was immediately subject to a social media grilling.