Emin Gün Sirer was quoted in a New York Times article entitled "How China Took Center Stage in Bitcoin’s Civil War". 
"Despite the talk of a borderless currency", the article states, "a handful of Chinese companies have effectively assumed majority control of the Bitcoin network. They have done so through canny investments and vast farms of computer servers dispersed around the country".  "The concentration in a single jurisdiction does not bode well", said Sirer.