My daughter, who has a hearing defect, was prescribed a listening program that only worked on - Windows 95.
This was in the early days of Windows XP, so finding a Windows 95 machine (or a set of disks) was somewhat hard.
I did manage to find one at a local electronics consignment store which claimed to have gone through and sanitized the system from the previous owner.
My seven year old daughter looked at the "Videos" folder and found somebody's collection of something that we could only described as "Jamacian Dungeon Porn". To use the vernacular of the article, these videos were not "pristine" and really quite disturbing.
She was pretty freaked out by them at the time and, ten years later, she still says she remembers the screams although she can't remember what was on the videos.
As for the store caring? We got the impression they were most upset at the idea we didn't save a copy of the videos for them.
I'm sure our story (and the one in the article) are pretty rare, but I can see the probability of something like this with "reconditioned" equipment is no where near approaching zero.