There's nothing theoretical about what's he's suggesting.
You'd be referring to BIS.org, the central banker's bank, which was setup in 1930 for reparation payments to Germany. The bank was almost dissolved in 1944 after allegations it facilitated Nazi Germany's looting of other countries assets. Two of its directors were convicted at the Nuremberg trials and one owned the bank used by the Gestapo. But the modern father of economics, John Maynard Keynes, was a prominent voice against its dissolution.
I believe the very existence of the bank was denied publicly for years. Today they have assets around $400 billion and are immune from any jurisdiction (based in Basel, Switzerland). There is nothing American about the Federal Reserve system nor its international counterpart, the BIS. It's an oligarchy and extremely corrupt. The reports of the BIS have numbers like "$147 trillion" referring to currency swaps etc. It's a fascinating look at how international banking works, all of which is public now.
As for the Liberty Dollar, it existed for around 8-years and had letters from the Treasury, Secret Service and others attesting to its legality. As soon as Liberty Dollar made millions of dollars in Ron Paul coins, they were indicted and their customer's property was seized. However, the Liberty Dollar's marketing plans for the promotion of their alternative currency were deceptive and likely illegal.