How did they destroy the data? (Score 2, Insightful)

How did they destroy the data? I assume it was stored on HD's (and probably backed up on tape). Did they use a DoD 5220.22-M wipe (or if there is an updated version, use it) on the HD's? Did they grind down the storage media? Or did they drive by a vacant street and toss the it out in the window into a storm drain?

Derelict