Maybe Because you have been quitting out of to many matches ie "Rage Quitting" you now can't join any matches for a certain time period.
Just like HALO hey
never left a match, still cant join
Try backing out to the main menu on BO2 then going back in. If that doesn't help, reset you gaming system.
David Vonderhaar just inform us via Twitter that the MP servers are back online.
CODBlackIce | Global Forum Moderator
Black Ops, Modern Warfare 3, & Black Ops II
Also, reference Vahn's latest post on "Game Servers are Unavailable".
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