I'm one of the people it happened too. My nephew was reading 1984 for his summer reading for 8th grade. He was not finished and I was annoyed. Eventhough it was removed from my Kindle, my nephew is reading it from my PRS-505
I removed the drm and made an LRF copy and loaded it to my PRS-505 and then loaned my nephew the PRS-505!
So Amazon removing the book from my Kindle and archive is a noot point since I have a non-drm copy on my computer!
I would be really angry if I had to go hunt for a paper copy of the book so my nephew could finish it.