That's not exactly what I meant honestly , I mean they are an exchange , they should have some kind of database where they watch addresses and the funds are stored and who sends to who etc... they should make some link and find out where It went exactly . (I really don't see it that hard since they know the time of the hack and how much is stolen etc... unless I'm missing something)
firstly bitfinex only has human identifying logs on their own deposit users/addresses. it would require OTHER exchanges to look at the taint of their future depositors to see where funds came from. this is because im pretty sure the "hacker" wont put funds back into bitfinex after that.
ok. so again,
let the hacker pay you a small amount and you then deposit funds into an exchange whether it be coinbase, bitinstant etc.
now the exchange reports it to the authorities that they have a user that has funds from the bitfinex 'hack'
the authorities request a warrant to enter the your home, using local authorities in the your area to search and seize all of the your computers to find evidence of a connection..
arrest you and question you for upto 48 hours.
i forgot to add in last post
freezing all of your assets, where you need to higher a lawyer and spend months and many thousands trying to claim your innocence in a hope to get funds released.
have a nice day
