Steve Smith, professor of History at the University of Essex, writes on The Chinabeat blog:
One of the intriguing aspects of the appalling crisis created by the earthquake in Sichuan on May 12—whose death toll as I write is over 40,000 and still rising—has been the role played by rumor. Just four days before the quake, the Sichuan provincial government issued a notice designed to quell “earthquake rumors.” Three days after it, on May15, Xinhua news agency announced that seventeen people had been arrested for circulating malicious rumors, and the Ministry of Public Security revealed that its bureaus in eleven provinces and municipalities had discovered more than forty messages on the internet that “spread false information, made sensational statements and sapped public confidence.”
In the weeks leading up to May 12, warnings of an imminent earthquake emanated from various quarters. Most significantly, Li Shihui, a scientist at the laboratory of geo-mechanical engineering of the Chinese Academy of Sciences, claimed on his blog that in April the seismologist, Geng Qingguo, vice-chair of the Committee for Natural Disaster Prediction at the China Geophysical Institute, had predicted a quake of 7 or more on the Richter scale in the Aba Tibetan and Qiang autonomous prefecture of Sichuan. On April 30, he claimed, the Committee for Natural Disaster Prediction had passed on a confidential report about his prediction to the China Seismology Bureau.