Read Book Glitch
We purged about 300 non-book items from the books read list for pets. From time to time, an item either glitches or a setting is accidentally changed and it becomes readable or collectible. We regularly run scripts to remove such items from collections, but we overlooked books read.
So about 300 Apples, Blob Kitties, and even Poo Hats, were removed from books read list and were placed back into the users' inventories.
Posted by 
Scarsdale