Microsoft has denied that Xbox Live has been compromised, although admitted that there's been outside access to "a limited number" of accounts.
Reports from all over the shop, including GAF and Reddit, indicate that hackers have gained access to their profiles and bought Microsoft Points, as well as FIFA 11 or 12 appearing on their gamercards.
Microsoft is currently sorting out the situation, but says the service as a whole hasn't been compromised.
"We do not have any evidence the Xbox LIVE service has been compromised. We take the security of our service seriously and work on an ongoing basis to improve it against evolving threats," said an MS statement to Ars.
"However, a limited number of members have contacted us regarding unauthorized access to their accounts by outside individuals. We are working with our impacted members directly to resolve any unauthorized changes to their accounts.
"As always, we highly recommend our members follow the Xbox LIVE Account Security guidance provided at www.xbox.com/security to protect your account."