Are you absolutely sure that DBAN works properly?

No.

There are several situations in which a DBAN failure could go unnoticed:

  • DBAN may fail to detect a hard disk in a computer with many hard disks. You must check whether DBAN actually detected all hard disks in a computer.
  • Your hardware caches writes or otherwise does not implement a functional write barrier. This is likely to happen with battery-backed large-memory RAID controllers or defective hard disks.
  • Somebody with a lot of time, money, and brains needs to recover your data.
  • The software that you downloaded could be bugged or trojaned. (Did you check the PGP signature?)

If you are seriously concerned about any of these situations, then consider drilling open your hard disk, grinding down the platters, and melting all of the parts in a furnace.

DBAN is still "good enough" for "most people".

If you need to externalize risk or outsource blame in a corporate environment, then you need an EBAN support contract.