This paper is crucial part of an experiment aimed to investigate whether Social Networks can be of help for Astrophysics. In the present case, in helping to eliminate the deep-routed wrong misconception of Flat Rotation Curves of Spiral Galaxies, more rapidly and efficiently than the traditional method of publishing peer-reviewed papers and organizing a number of international conferences. To reach this goal we created the Facebook Group "Rotation Curve are not Flat" that we filled with all the evidence necessary for an immediate and definite confrontation with the above fallacious legendary belief. In this paper, we solicit the interested Astrophysicist/Cosmologist FB users to join this group. Finally, the paper informs the Astrophysical Community that a widespread belief is instead an hoax, whose consideration may slow down the progress of science and that must be taken care by innovative means of communicating scientific advances. This test case may anticipate the future in which Web n.0 will become an effective scientific tool for Astrophysics.
