Hackers are gaining access to Xbox Live accounts

Hackers are gaining access to Xbox Live accounts, and may have been for three years or so; apparently, Halo 3 multiplayer producer Joe Tung is a recent victim.
It seems social engineering is the key tactic, with hackers tricking details out of both users and customer support operatives:
The danger stems from the apparent failure of Microsoft customer service to keep track of repeated account access, our expert said. This allows hackers employing social-engineering tactics to call support lines without being tracked. A hacker can then use this information to gain access to a user's Xbox Live gamertag, which typically has a credit card attached.
Access to a gamertag can also mean access to a Windows Live account. Windows Live is Microsoft's proprietary log-in service. You use it when accessing account information on Xbox.com, but users who strictly use their Xbox 360 might not even know what Windows Live is. With Windows Live access, a hacker can change which gamertag and e-mail is associated with that Windows Live account, preventing a user from recovering their gamertag and creating a mess of confusion for customer service when investigating.