Somehow until today I had never heard anyone use the term Human Flesh Search Engine which, according to Wikipedia,
…is a primarily Chinese internet phenomenon of massive researching using Internet media such as blogs and forums. It has generally been stigmatized as being for the purpose of identifying and exposing individuals to public humiliation, sometimes out of vigilantism, nationalist or patriotic sentiments, or to break the Internet censorship in the People’s Republic of China. More recent analyses, however, have shown that it is also used for a number of other reasons, including exposing government corruption, identifying hit and run drivers, and exposing scientific fraud, as well as for more “entertainment” related items such as identifying people seen in pictures. A categorization of hundreds of HFS episodes can be found in the 2010 IEEE Computer paper A Study of the Human Flesh Search Engine: Crowd-Powered Expansion of Online Knowledge.
The system is based on massive human collaboration. The name refers both to the use of knowledge contributed by human beings through social networking, as well as the fact that the searches are usually dedicated to finding the identity of a human being who has committed some sort of offense or social breach online. People conducting such research are commonly referred to collectively as “Human Flesh Search Engines”.