Scary Federal Prosecutors
What can be terrifying about Federal prosecutors is that, having spent time and money trying to build a case, but failing to do so, they will look to indict on something else - something peripheral - anything, really, in order to justify their effort. The measure of the success of prosecutors is their ratio of indictments, not justice and fairness. They really cannot stand to let anyone out of their clutches - it makes them feel like they have failed.
Eg Martha Stewart: No underlying crime, but a problem with her ill-advised testimony which she innocently delivered without benefit of counsel. I've seen this sort of thing all too many times, and people's lives destroyed by it. Giuliani was a master of this when he was a prosecutor, and who remembers how many of his famous Wall Street arrests were followed by dropped charges, or Wall Street convictions were reversed, leaving a swath of human destruction behind? Yes, he had few reversals, but his reversals were the front-page arrests. Watch Fitzgerald try to do this with Rove and Libby now that they will not be charged with violating national security laws. They could get indicted for jaywalking while crossing the street to the courthouse. No-one's life can withstand the kind of scrutiny these guys can put someone under, and they do not think twice about sacrificing some poor soul when their careers are at stake.