Rikkitic:timmmay: Sony was a traditional corporate hack I think, nothing cloud related. Haven't read all the stories though.
My point was really that nothing connected to the Internet is secure, regardless of claims. Cloud storage is connected to the Internet. Ipso facto.
Maybe nothing is perfectly secure, but that's mostly because people require convenience. Systems can be made very very secure using techniques like encryption with good key control and two factor authentication. Few people use them well, and social engineering can circumvent security if the systems aren't set up right.
I'm a certified Amazon cloud architect, know a thing or two in this area. Hard to write much on phone though.
One system I'm designing that will handle sensitive data has an air gap - ie not connected to internet. Not necessary as I could secure it other ways but it's easier, less testing required in some ways.