The Psychic Gambit.
Everybody remembers the prediction the pyschic got right. Not as many remember the predictions he got wrong. Drudge will headline a story on slim evidence. If it pans out, and he's the first one to spread it widely online, he's a genius. If it doesn't, a correction or clarification later in the day takes care of it.
Usually, it's clear in the story that the source is not a solid one, so to anyone paying attention, it's not a serious problem.
As with any other online source of information, you have to judge the source for yourself.