It is generally believed that the Internet, as a public-opinion field of multiple information sources, should have the ability to refute rumors and correct the falsehood on net spontaneously. Employing a series of research methods like case study, survey and in-depth interview, this study finds that such ability of the Internet theoretically exists. However, due to influence of a number of factors, the Interent can only purify rumors and false information partially and conditionally. <<