I was in a bookstore today and I saw a coloring book called "Tolkien's World" which was based on characters from The Lord of the Rings and other works by JRR Tolkien. On the back cover, it said:
This book is unofficial and is not authorised by the Tolkien Estate or HarperCollins Publishers.
How can the author and his/her publisher get away with that? Surely the publication of the work is going to infringe on the copyright of the Tolkien Estate and HarperCollins? I would have expected publication of the work to have drawn a lawsuit, but it's clearly been in print for a couple of years.
Disclaimer - I have no background in law.