Grigory Rodchenkov, the former head of Russia's drug testing laboratory, outlined a very sophisticated process where they'd swap out samples of dozens of Russian athletes. Two other colleagues of his have died "coincidentally", he fled the the US.
http://www.reuters.com/article/us-sp...-idUSKCN0Y32GI
Canadian athletes speak out:
http://news.nationalpost.com/sports/...oping-in-sochi