Summer Olympic Games demand for tickets to all levels of each event, there was controversy when seats set aside for sponsors and National Delegations went unused in the early days. A system of reallocation was put in place so the empty seats were filled throughout the Games. Rio de Janeiro, Brazil hosted the 2016 Summer Olympics, becoming the third city in the Southern Hemisphere to host the Olympic Games after Melbourne, Australia, in 1956 and Sydney, Australia, in 2000, and the first South American city to host the Olympics. The preparation for these Games was overshadowed by controversies, including the instability of Brazil's
Doping at the Olympic Games that were collected at the 2006 Turin Games. In 2014, the Estonian Olympic Committee was notified by the IOC that a retested sample from cross-country skier Kristina Šmigun had tested positive. On 24 October 2016, the World Anti-Doping Agency Athletes' Commission stated that Šmigun, who won two gold medals at the Turin Games, faces a Court of Arbitration for Sport hearing before the end of October. If Šmigun were to be stripped of her gold medals, Kateřina Neumannová of Czech Republic could be elevated to gold in the 7.5 + 7.5 km double pursuit event. Marit Bjørgen of Norway could