Selvec said:
Yes you can recover data from an HD, but if you no how, you can completely destroy any data on one, beyond recovery. Just that the average computer user doesn't know.
Used to drink with a bloke who freelanced in forensic data recovery for law enforcement and private investigators and he said 95% of the hard drives he got handed were single reformats with busted up cases... which did absolutely nothing to destroy the data and could easily be restored in less than a day (and that's assuming a full HD platter swap into a working HD).
Magnets aren't too bad but they have a tendency to leave big chunks of artifact data.
We experimented with ways to destroy data beyond his ability to recover it and came up with a few good ones, including one that reinforced my belief that there isn't a problem that can't be solved with detcord.