"Before a decommissioned encrypted storage device can physically leave our custody, it is cleaned using a multi-step process that includes two independent verifications. Devices that do not pass this wiping procedure are physically destroyed (e.g. shredded) on-premise"

Why not just shred all decommissioned disks? Someone must be buying them for enough money that Google created a multi-step process for cleaning and verifying them. Presumably Google keeps disks in commission until they're no longer economic in their own operation.

So, does anyone know about the operation that makes profitable use of disks that are no longer economic for Google?