I'd say, Banque Worms ruling as we've found out can always be at play. Cough $900,000,000.00 accidentally transferred a couple years ago from a large bank to lenders.
By this definition, isn't for example USD a ponzi? Afterall, it is a Fiat currency now and not backed by a commodity. If I received wampum back that would offset it no? How does taxes/gdp protect you if taxes are of their self made up of USD.