Battlefield 3 servers and the associated Battlelog service have been the target of a denial of service (DDOS) attack, and a planned double XP weekend planned to start today has been delayed as a result. EA and DICE are working to restore the services.
"As a part of our efforts to resolve these issues, we've conducted rolling restarts of Battlefield infrastructure servers to apply some updates," the post states. "Thank you for your patience and support while we work to get everyone back and playing Battlefield 3 as soon as possible."
A tweet from DICE also noted that the double XP weekend has been postponed indefinitely, while these problems get sorted out.