China already does this ‘black market’ organ harvesting from its prisoners.
http://en.epochtimes.com/news/7-1-24/50806.html
CHINA—In the middle of January, 2007, the BBC Chinese website published an interview regarding organ harvesting in China. For the first time, China’s Ministry of Health spokesman Mao Qunan admitted to the practice of organ harvesting from executed prisoners in China, which he had publicly denied before. However, Mao evaded key evidence of organ harvesting from Falun Gong practitioners and denied that accusation.