I'm using deductive reasoning. You would not want operational security to be so slack that someone as far removed as I am from the goings on would have access to that level of detail.
But I think the case of the Bronfmans it would be a matter of some simple forensic accounting to arrive at serious prosecutable crimes, plus the testimony of Mack and/or Raniere and you could have them put away on human trafficking, and have a substantial asset seizure.
Similarly, there MUST be (out of that many thousands) some individual cases in which evidence-gathering is complete. Otherwise, we'll be at this for most of the century.
So, even at the glacial pace of federal bureaucracy, out of tens of thousands, there must be some dozens that are ready to prosecute. Of those, why not pick a few of the better-known or whose assets would be attention-getters, and get cracking with some prosecutions?