Bitfinex, for example is being prosecuted. The SEC have cases against a few of the mid-level people, but the founder is hiding out somewhere in Asia, and will never see the inside of a US courtroom.
Also, it's very easy to con someone, but it's almost impossible to convince someone who has been conned that they've been cheated. If you do your due diligence, and disclose your findings, the marks will ignore you, the con artists will smear you in the press, start lawsuits against you, and everyone uninvolved will shrug their shoulders and 'both sides' your feud.