What would be the point? Suppose that at some point of time in the future, an individual is found in possession of some of the stolen coins - e.g., because he paid for something with part of them and you were monitoring all addresses that have received them and he didn't try to hide his identity.
What then? Is this the hacker? You have no way of knowing. He can say "I bought some via Localbitcoins in a cafe from somebody I've never seen before and who didn't tell me his name, maybe they are from there".
We can follow all transactions involving the stolen bitcoins but unless you can discover the identity of the person behind every single one of these transactions, there is no hope of catching the thief.
One step at a time.
Right now, the hacker is mixing the coins.
Next step will probably to be forgotten.
Next, he should be mixing them again just before exchanging them for cash.
At that last step, he takes a risk.
Thanks. I PMed him.