Internet provokes a double effect on rumors: it lets diffuse it more than ever and, in the same time, gives the power to control the occurrence of a suspected rumor. In this aim, some specialized or "reference websites" are available on the Net. The text of this communication presents some of them: the first one, AFU in 1991, was the FAQ of the newsgroup alt.folklore.urban. Thereafter were hoaxbusters.CIAC.org (1995) and Snopes.com (1997), and a couple of "sequels" (Urbanlegends.about.com, 1997; Truthorfiction.com, 1998; Hoaxbuster.com, 2000). Finally, some questions will arouse from the fact that none of these websites seem to have any means of investigation, neither any routine method.