What’s the limit on that? Dollars or time? I would be beyond furious if I was expected to help make someone else whole.
I fully empathize with the absolutely epic degree it must SUCK to get a call and be told "yeah that 10% you've been earning for the past 20 years was actually someone else's money, you need to give it back."
My reply would be along the lines of: "Sorry lost it all in MtGox/FTX/Crypto/Vegas/Horses"
Such are the wages of being a beneficiary of a ponzi scheme. It would be a good incentive to do better research.
If the argument is, “Nobody is that good, you should know better”, does that mean Buffet’s scheme will start crumbling any day now?
You have two options.
1. Don't be unlucky. [1]
2. Or, you can make sure your society has socialized old age pensions, and that it puts in the work necessary to keep them solvent, and its citizens taken care of once they are past their working years.
[1] The easiest way to not be unlucky is to buy into a boring, diversified index fund. Berkshire may be a fraud, but it's unlikely the entirety of the SP500 is.
I mean, if you unknowingly buy stolen property, it will be just taken from you if the police finds out. I don't see how that's different.