Recon armor theft in Halo 3 shows that an Xbox Live account can be hacked.
A few readers might remember the story of Syllus vBi, a 360 user who was rewarded with an ultra rare set of recon armor by Bungie after he managed to shoot himself in the head with a sniper rifle during a multiplayer match of Halo 3.
Most could not care less that this special armor was recently stolen from Skyllus' account, and that he's been crying about it quite a bit on his clan forum and Bungie.net.
He also seems to have kept in touch with the hacker who wronged him by sending messages to his own account through an alternate Silver one. I personally want to know what he's going to do with the armor, considering the fact that using it would make himself a flashing beacon giving away his exploits.
Microsoft apparently refused to take notice at first despite his many attempts to catch their attention through customer service; until it somehow dawned on them that this armor-mishap could escalate into a more serious threat for other users.
As Skyllus pointed out in his own posts, this violation of privacy reveals a potential vulnerability in Live's security, one that other hackers (or the same one) may tap into. Anyone with malicious intent could hijack your account, steal your information, alter your settings... so on and so forth.
Nothing definite has been released yet, but if Live hacking becomes some sort of trend, I can only imagine those pompous PC versus Mac jokes evolving into 360 versus PS3 bastardizations.
You could just tell them your name and then say I need my credit card #'s and they would supply them!