Somewhere in my basement is a box that has old hard disks, going back to when they were only 2 gig in size. Only ones that I've ever let go of were wiped using a utility program, or ones that were "slow" formatted (instead of quick formatted) when they were repurposed in computers I've given to other people.

On the flip side, there's been a couple computers people have given to me as spare parts that they said "didn't work" that I've recovered files on and aked them if they needed. They usually say "huh? the disk's broken" when it was just the boot sector or something that didn't work. I then tell them they need to be more carefull and wipe those disks.