Simple enough question you'd think :)
You're looking for a cloud storage provider, whether it's for collaboration or for backups or whatever.
You look at various vendors from small names to big names and they all say they're HIPAA, SAS 70 etc.
At some point you need to decide if you're comfortable putting corporate data out there.
Given that not one of these cloud providers will accept any kind of liability if they get hacked it seems it ultimately comes down to a leap of faith, "Trust us we're a big name and we're really nice people", that kind of thing.
Am I missing anything?