After reading the article, it reminded me of an incident I had back in the film camera days. I was shooting with a medium format camera (very large film) and on a 4 week trip with lots of film both checked and in carry-on.
After getting back and tracking my travels - I had 15 rolls ruined by an x-ray machine in Greece.
This proved for me at least that machines can be set at levels that can really mess things up.

Perhaps there is a level that be set that will mess up a kindle