It is still too early to say how bad it is, but it does beg some pretty big questions on how Sony treats personal information of their customers ...
I have been involved in the creation of several systems that hold personal data, and every system I have built has been designed with the intention that even if a hacker did get access to all of your information none of it was stored in a format that would provide much benefit to them. Credit cards, passwords, and other important information should either remain unstored or be hashed/encrypted to prevent them from being stolen.







