I haven't heard of the story before, interesting read, thanks!
I think the thief should start sending small amounts to random active addresses, even member addresses found on this forum. That will make the number of address to monitor explode exponentially.
And why in the world would the thief do that?
It's better for the thief to wake up 20 years from now with 1 billion dollars and their head intact, rather then 10 billion dollars and their head on a pike somewhere.
But then again, some people like to take their chances.
That said- tracking them will be childs play once google gets into the blockchain analysis game.