e-books are very tricky when it comes to copyright. Even the retailers who sell the ebooks on Amazon (or elsewhere) are not really the "owners". It's always the publisher who is considered to be the owner. So technically you do not own the ebook you bought, you just license it for yourself on your device(s). [0]

Isn't there an ongoing lawsuit against Amazon on this issue where someone is suing them for misguiding people about ownership when you "buy" an ebook from them?

[0] https://goodereader.com/blog/e-book-news/this-is-the-big-rea...