When running a Ponzi scheme, how does one avoid enormous, unexpected withdrawals - runs on the bank, so to speak - that would pull back the curtain and reveal a little man blowing smoke? One way would be to attract a core of investors who could be counted on to never withdraw more than a small percentage of principal each year.
I know that plenty of folks have issues with Social Security, but I'd urge them to confront it on its own terms. Calling it a Ponzi scheme is misleading and does more to cloud the issue than it does to illuminate it. And yes, I do know that unless changes are made, the current system is unsustainable. But that doesn't mean it's fraud.