I never understood how transactions were supposed to be anonymous if every single one ever made was recorded on the blockchain. The argument a long time ago seemed to be that the sheer volume of transactions would make it impossible to reasonably handle, but in the past couple years I’ve seen more and more stories where the FBI has tools that let them trace transactions and use them in arrests of people engaged in crimes that have netted millions of dollars. Maybe right now it’s still only worth doing on major crimes, but I assume it will only get easier and more available with time.