Today a chat exploit was brought to our attention. It allowed authenticating as any username on the chat servers. By specifying a username and any chat authentication key, you could chat as anybody. That has now been fixed and unlikely to have been used/exploited by anybody outside of discovering the exploit.
This, however, did not grant access to ones account. All of that information is safe and no action on your part is needed.
Big thank you to pizzabiceps that alerted us of this exploit! We have given them one year of VIP Gold for free as a thank you.