Interesting. But to be fair, the poster at reddit doesn't mention Bitfinex specifically, so there is the chance that it was another exchange that was exploited. It could even be Gox that was exploited! (maybe that would explain why they are not allowing BTC withdrawals! They are upgrading their security so it doesn't happen again!  )

But I think Bitfinex's issue was different, it seems actually trading and borrowing was required for the exploiters to make money. Also try withdrawing 100 BTC from Bitfinex and you'll have to wait for it to be processed manually. While a 100 BTC withdrawal from Gox would likely be automatic (before they stopped BTC withdrawals).

Maybe Giancarlo can clarify whether it was Bitfinex that was contacted about this issue, if not it was probably Gox.