My account was hacked about a month ago (July 18th, to be exact...)
The hacker bought 75$ worth of xbox live points at about 6am. I called Microsoft within an hour of it happening, got the account reset back to my xbox, and the money restored from their purchase to my account. After getting off the phone and being told multiple times not to use the points, I monitored my account closely and maybe fifteen minutes later of my account being supposedly locked, the hacker purchased Call of Duty: Black Ops.
Thankfully, Microsoft was pretty good about it all.

They had my account locked down for a couple days while they investigated, and then I was back up and running.
A little over a week later (July 28th), I got an e-mail from some random person named Wendy, who said they had purchased COD: Black Ops through ebay, and was given my e-mail address. Yup - the scammer tried to SELL my xbox live account on ebay.

I reported that transaction to microsoft and to ebay / paypal.