Case documents and information here. The impression I get is that they were using methods related to 1099OID, Doug Riddle, Tim Turner (?) and issuing "Money Orders" in some manner. I haven't seen a copy of the money order they allegedly issued. Seems they are keeping out of case jackets the issues. But from the charges they were likely issuing the MOs payable against the U.S. Treasury. Related transcript document here.
In all honesty acceptance of a can be done lawfully and there are lawful and workable methods for handling debts to the IRS. I'm not sure why so many people have an aversion to sitting down and reading a book on bills of exchange, promissory notes, money securities--but will risk so much on what "he said".
Another related complaint is attached here: Attachment 2782