You tell everyone that you have secret information with evidence that you can't show yet. But to prove your own credibility, you make your statements about the future somewhat coded and ambiguous, open to several interpretations. Your readers, who want to believe your secret information and that they are on the cutting edge when they listen to you, subsequently interpret some of your vague statements as accurate predictions of current events (and ignore the statements that they can't match to anything....yet!) Sort of like how horoscopes and fortune telling work.