Hoaxes are one way for activists to “buy” some airtime that they can’t afford. Instead of complaining that the press is set up to give voice to the interests of the powerful, the hoax puts that bias to work. By speaking as the powerful, and telling a more interesting story than the powerful usually do, one can often commandeer a pretty big soapbox. After the hoax is revealed (usually within minutes or hours) then the activists can explain themselves to the public in their own true voices, with the help of the usually massive numbers of journalists all stirred up by the trick that’s just been played on the powerful.
An Example
In 2009, The Yes Men distributed over one million copies of a fake edition of the New York Post (headline “We’re screwed”), which contained stories about the real effects of climate change.