I am doing research on China's hot job market and came across some real scary stuff about numerous scams. They are targeting recent grads, the unemployed, and even senior citizens. There is one group in the U.K. that uses two different companies (operating from the same address and listed telephone number) that are running the same identical China internship scheme.
There web site is amazing and they have about a dozen great reviews which I think are all self-created. The scam companies are OnlineTEFL.com and i-to-i.com. They may not be the biggest fraud but they appear to be the oldest judging by the dates of the complaints - starting as farback as 2007 and running to date.