Same thing happened to me. When I turned on Black Ops II this morning, it stated that my data was corrupted and would reset back to the latest level, but it reset my rank back to level 1 from prestige 9 level 30. I have committed no infractions what’s so ever, so I’m a bit puzzled as to why this happened. I logged onto multi player online, but I had the only reset of the two.
I sent a private message to cutpurse, so I'm hopeful things are resolved very soon.