It all depends on you, you will be surprised to see all the victims of something like this before. If you look at how many previous hackers tried to keep their transactions secret but could not keep their secret information was finally hacked to others by the police. I don't think there is any way to hide the transactions of online platfrom. Hackers are constantly discovering new things that I am surprised to see or know.
Nah, pretty sure they're not fully understand and carefully how to hide their taint 100% from anyone. He must leave a trace on centralized exchanges or ever submitting his personal identity to someone, that's why the police can discover the hacker is. However when someone want to protect his privacy, it doesn't mean they're a hacker, criminal or a bad guy who have doing something wrong. They just want to live a comfortable life without bothering them.