Hacker of woozworld

So the message we got from woozworld from a guy named Eric Brassard. Well I didn't read closely to the information since I was too busy freaking out that I won't be on woozworld for more than a week (I haven't lasted a week without woozworld) But I noticed THIS:

Although we are still investigating the details of this incident, we believe that an unauthorized person has gained access to the following information that you provided: email, age, encoded password and username. It is also possible that your profile data, including purchase history and related email username may have been obtained. There is no risk for your payment information (credit card number, phone number for sms payment or pre-paid card number) since they are not stored on our servers.

So whoever got into woozworld got our EMAIL,AGE,PASSWORD AND USERNAME ( Note to VIPS: I believe the code for your/parent's code number from the credit card you have on woozworld DX) So he know knows our Email Age,Password,And username. When woozworld comes back There can be a chance the hacker might hack our accounts. But part of the message says we should change our email,password,and username. (NO WAY I AIN'T CHANGING MY USERNAME EVEN IF ITS FOR PROTECTION! I LOVE CUPCAKES)
I think the hacker would be DD. The questions I have is : WHY would he hack woozworld? WHAT DID WE DO TO HIM???