I don't think comparing a service like S4 to a non-existing disk is fair. Especially in enterprise software, I often get the requirement that the data is reliab

I don't think comparing a service like S4 to a non-existing disk is fair. Especially in enterprise software, I often get the requirement that the data is reliably written. I can easily point an auditor to the S4 service contract and SLAs to prove we fulfill this. A bespoke arrangement of floppy drives and shredders might pass if the auditor's having a good day. But removing the disks entirely? That will never fly.