ABSTRACT
People occasionally wish to discourage the emergence of certain rumors. In the United States during 1960s, for example, authorities in many big cities tried to prevent rumors from circulating that experience had shown would inevitably set off race riots. Most big American cities where there was a high risk of race riots set up specialized information centers starting in 1968, known as rumor control centers. Their goal was to find and disseminate exact information corresponding to the questions city dwellers asked them over the phone. As rumors often arise from distrust of official versions, a key to prevention is also the credibility of sources. This trivial recommendation poses, as one shall see, serious practical problems. In order to be considered credible, it is not enough to say that one is; one must have proofs of credibility to back one up that is, one must be someone who has always told it like it was.
