Hopefully their customer database, including emails, has not been stolen as well during the hack as if it was most likely it will show for sale on some black markets and there could be more phishing emails trying to steal crypto coins from users.
It is also possible that somebody is using the user database that leaked from the MtGox hack a while ago and/or from other exchange breaches to send phishing emails hoping that the same users also had accounts on Bitfinex.