This study examines how people manage the surge of information in dynamic situations. When faced with uncertainty during a disaster event, people tend to experience anxiety and fear. In August 2009, during the disastrous floods brought by Typhoon Morakot in Taiwan, a new form of communication facilitated by the latest communication technologies and social media emerged. Ad hoc disaster information websites effectively collected and organized disaster-related information from various internet communities. Through collective gatewatching, these websites developed a unique technique to ensure the accuracy of information. Thus, social media has become a new platform for spreading information and factchecking.