[/img]Here’s what the latest Xbox Live service alert does say: “Are you experiencing issues when you try to sign into Xbox Live? Our team is already investigating these reports and we hope to get things back to normal ASAP! Thanks for your patience while we get this worked out. We’ll update you on our progress in 30 minutes.”
The alert may stop you doing one or all of the following while playing games on Xbox 360 and Xbox One: Managing friends lists and tracking what friends are doing and signing into Xbox One.
At the time of writing the alerts are the following
Xbox One - Signing into Xbox Live
Xbox 360 - Joining other Xbox Live members in online games
Source: TheTechGame.com