Earlier quoted context omitted.
Except for the AWS EBS outage a couple of years ago which had nothing to do with a security breach. http://aws.amazon.com/message/65648/ Cascading catastrophic failures do happen that don't involve security.
I'd think that Apple would be happy to tell us it was a simple power/network failure were that the case. Sudden shutdown of vital service + silence = most likely a security prob. I'm not saying that's what it is but it seems likely.
IMO not communicating with the outside world is a fail, but I've seen delays in this when small teams suddenly get swamped.