China's internet vigilantes and the 'human flesh search engine'

Last month a Chinese official in charge of internet surveillance gave notice that mobs of web users who turn on individuals and make their lives a misery will not be tolerated. In China it happens often and on a massive scale, earning the phenomenon the title of the "human flesh search engine".

On Thursday 21 March 2013, the world changed for Yin Feng, a self-described "average guy" who worked as a part-time taxi driver in the western Chinese city of Urumqi.