Some of the other response in that Reddit thread are pretty eye opening too. One user, who has been told that his account is going to be locked on January 31st if he does not provide years old information regarding source of funds, says he cannot provide this information since he no longer has an account with exchange the funds came from and they have been unable to help him. Other users say that funds came from exchanges which no longer exist at all, so there is no way of providing proof of source. The response from support is: "I suggest you try to contact them."

I fully expect there is going to be a flood of complaints against Bitstamp in the coming weeks. There will be a number of users who think they have provided all the necessary information only to find that their accounts are locked anyway, and there will be a number of users who are completely unaware of this entire situation. All these users will then be hit with excessively invasive requests for KYC and other information which they either do not want to provide or may be impossible to provide, as the information Bitstamp are asking for simply doesn't exist. All these users will have their accounts frozen and their bitcoin essentially held hostage.

Unless you are comfortable handing over details of your entire financial history, from standard KYC through to your salary, copies of your pay checks, your complete bitcoin transaction history and holdings, and so on, then you need to get off of Bitstamp and other centralized exchanges now. Given the chaos from a database of only names and addresses being hacked, I can't imagine the fallout when one of these databases of financial histories is inevitably hacked.