I think that this has little to do indeed, bitcoin is a new theme for this and too complicated. But soon this, too, the problem also shows up in this sphere of activity. So be on the alert.
For me it is true that many criminls right now is also using bitcoin and i dont really think that police can't stop the criminals to used bitcoin, becauase we all know that butcoin is open for everyone and that is the biggest disadvantage of bitcoin.