At least if Bitcoin made criminals filthy rich, they should be less likely to look for ways to steal someone else's hard earned money, rather sitting on a beach in the Caribbean somewhere. I doubt many criminal masterminds made a fortune, the whole point of it for them was to spend it anonymously, so unlikely any amassed a huge fortune, although I'm sure some must have done with the law of averages. I heard about Bitcoin about 5 years ago, but unfortunately never did anything about it.