If people disagree, I'd love to know why.
In particular, I'd wonder what the cashflow behind dark drug markets looks like in comparison (not that I think that should be illegal, and yes, I accept that any data there would have to be estimates at best)
Legitimate businesses in the bitcoin space make small margins on each trade/transaction/etc. (Drug dealers are obviously a little different, but they are in the business of unlicensed pharmaceuticals, not the business of Bitcoin.)
Thieves, on the other hand, will take the whole thing, and run.
This is exactly what I meant. I guess I could have been more clear about that.
I don't have any data to back the assertion, and honestly I kind of forgot the markets were still extant, I just happen to know that people are making millions in illicit profits from these two methods, and I've never heard of a successful preminer (which was how I interpreted "Ponzi scheme") other than Mr. Nakamoto.