On the responses of social networks´ to external events

The paper reviews and complements the knowledge on the social network responses to brief duration events such as earthquakes, attacks, and aviation crashes. The main question asked are (i) if the number of posts related to such events is a credible source of information for assessing the number of people affected, and (ii) if the early information obtained from the momentary number of posts can be used to derive the further dynamics of the response of the social network to the event. Limits of the use of social networks responses for the above purposes are emphasized.