Simple, a financial crime. Just because people try to be decoupled from the government doesn't mean laws don't apply to them. Also as a side not operating a m

Simple, a financial crime. Just because people try to be decoupled from the government doesn't mean laws don't apply to them. Also as a side not operating a mixer without taking protocol about who used it when in which way is pretty clear cut money laundering. Hence why mixers are either exchanges which take your personalities or operated as much anonymous as possible and from countries in which they believe they can avoid the law. (EDIT: Yes there probably are people which operate a mixer without such precautions, and they might end up pretty bad if a country purses money laundering charges and it doesn't even need to be their country.)