Xbox Live service has issued a service alert, and this time the notifications are for issues with Call of Duty: Black Ops 2 and Battlefield 4 multiplayer on Xbox 360.
If you're playing either, you may have trouble "accessing all game features" or "joining other Xbox Live members in online games". Apparently all this is due to scheduled maintenance on the part of EA and Activision. We'll provide an update when more information is available.
Stay tuned for further updates!