Hi cee-dee!  I don't know of any.  Usually the mainstream media (the fourth estate) blows the whistle and pulls the plug when the evidence of wrong doing becomes visible enough.  That's what happened with Watergate, for example.

The nearest that the goofy fringe ever came to a real expose (as far as I can remember, anyway) was when the staff member on the National Enquirer contracted anthrax from a letter received in the mail, and died from it.  That was shortly after 9/11.  Definitely NOT the best journalistic technique....