So they hide it. Surely every self-respecting businessman has the means to anonymize his transactions. After all, if they knew about their money (they are not always honestly earned), then they would be in prison. I know that there are bitcoin mixers (they look like this https://bitmix.biz/en), which mix your money with someone else's, during a transaction, as a result, it is impossible to track the movement of funds and who it belonged to.