A key witness in insider trading trial "U.S. v Whitman" is Roomy Kahn. She had been an FBI informant for about five years before the federal government had its case locked up against Galleon Hedge Fund. In return she could receive a sentence less than the 30 year one she faces.
As Bloomberg reports, Kahn testified that she passed non-public information to defendant Doug Whitman of Whitman Capital. It was related to Google and Polycom. On the stand, Kahn tearfully admitted she had lied a lot to the FBI even when she was an informant.
So, no newsflash, Whitman's lawyers used that to question her credibility. How does anyone know that she isn't lying currently in that courtroom. The prosecution could be taking a risk staging her as a key witness, given the history of lies. Also, who wouldn't cry who's facing 30 years in prison. The tears could have come across as a nuisance.
On the other hand, the feds could be leveraging both Kahn and the many many lies, even if she is lying now, as a peek into the huge network of insider traders: A bunch of liars and thieves. It would not be hyperbolic for the prosecution to use the term "epidemic" to describe the practice. And to further classify it as a "cesspool."