I think your biggest enemy against any observer, passive or active, is still the 

. And if you're a true criminal, I think that active subpoenaing and raiding of insecure services that cannot be coerced into cooperation, will truly make this difficult.

Not to mention complexity but that could in theory be overcome with really good software.

AskSN

econ

Can You Safely Launder Bitcoin? And How Much?

denlillaapan

I think your biggest enemy against any observer, passive or active, is still the [`"Shapeshift heuristic"`](https://arxiv.org/abs/1810.12786). And if you're a true criminal, I think that active subpoenaing and raiding of insecure services that cannot be coerced into cooperation, will truly make this difficult.

Not to mention complexity but that could in theory be overcome with really good software.