Case in point, you cannot destroy data if someone wants it bad enough... 99% of the data recovered from hard drive from Space Shuttle Columbia

Gizmodo - Charred Hard Drive from Space Shuttle Columbia Recovered (Best Data Rescue Ever?)

"

It's taken four and a half years, but the data recovery specialists charged with extracting data from a cracked, charred 400MB Seagate drive aboard the ill-fated Space Shuttle Columbia have done their duty, retrieving 99% of the information written to the disk. The Columbia burned up on re-entry on Feb. 1, 2003, over Louisiana and Texas. Computerworld reports that the drive was found in a dry lakebed and handed to a team at Kroll Ontrack about six months after the tragedy, but the successful recovery has only just come to light.

...

The drive, already eight years old at the time of the mission, took a beating in the crash, and took another beating during recovery. Stripped down to the platter alone, it was placed in another mechanism and "carefully aligned" with a new motor. As it spun, it sustained more damage, but didn't crap out before Kroll could get the goods. ...

..."

As I've said in the past, once you create data it's very hard to destroy it.

Look, if the data off a hard drive from a space shuttle that disintegrated on reentry from orbit can be recovered...