EDIT: Exploit Resolved.
I am here on behalf of PIVX, please take heed of the following message.
A flaw has been found in the base libzerocoin protocol that has created an exploit that has affected ALL Zerocoin based privacy coins. This includes PIVX, as such all exchanges and service providers must place their wallets into maintenance mode and stop deposits/withdrawals. Not doing this presents a vulnerability to your service.
I would like to apologize for this troubling news. Our team is working on it at this very moment and hopes to have it resolved soon. I again, apologize for this inconvenience.