From iCloud's ToS, it looks like it'd depend on whether a court finds this to be either "failure to use reasonable skill and due care" or "gross negligence":

APPLE SHALL USE REASONABLE SKILL AND DUE CARE IN PROVIDING THE SERVICE. THE FOLLOWING LIMITATIONS DO NOT APPLY IN RESPECT OF LOSS RESULTING FROM (A) APPLE'S FAILURE TO USE REASONABLE SKILL AND DUE CARE; (B) APPLE'S GROSS NEGLIGENCE, WILFUL MISCONDUCT OR FRAUD; OR (C) DEATH OR PERSONAL INJURY. [Blanket disclaimer of liability in all other cases follows.]

I'd be curious if there is any good precedent on product liability for cloud services.