Microsoft said Saturday's lengthy outage of the Xbox 360's Xbox Live service was due to a "networking misconfiguration" and denied that a hacker group was in fact to blame From Neowin:

On Saturday, owners of the Xbox 360 console were unable to log into their Xbox Live accounts for several hours. Microsoft has now fixed this problem but some online rumors apparently claimed the outage was due to a hacker attack.

Today, GeekWire.com reports that they received a statement from Microsoft which states the real reason for the downtime. It also debunks the hacking reports, stating, "The Xbox LIVE service outage on 13 April resulted from networking misconfiguration during routine maintenance and was in no way related to false claims of hacking the service."

 Microsoft debunks rumors of hackers causing Xbox Live outage