Amazon has concerned many by automatically deleting books bought for the Kindle platform at the publisher's request.

Two e-book titles were remotely deleted by the company and their buyers' accounts have been credited with the full purchase cost. Ironically, the two books are George Orwell's Nineteen Eighty-Four and Animal Farm.

The publisher of the titles decided that it did not wish to continue selling them through Amazon, and pressured the company to delete them. The stealth move has upset many customers, and it is not clear that Amazon acted within its rights under the standard terms and conditions.

"Animal Farm by George Orwell, published by MobileReference (mobi), and Nineteen Eighty-Four (1984) by George Orwell, published by MobileReference (mobi), were removed from the Kindle store and are no longer available for purchase," said Amazon customer services.

"When this occured, your purchases were automatically refunded. You can still locate the books in the Kindle store, but each has a status of not yet available. Although a rarity, publishers can decide to pull their content from the Kindle store."

Users on Amazon's forums have been up in arms about the move, with some likening it to a bookseller breaking into a house to retrieve books it has decided it doesn't want to sell after all.

"I would have a serious issue with what they did, and no, I would not delete a paid for book off my PC, regardless of whether or not Amazon refunded my money," wrote one.

"If I bought it legally, I'm not deleting it just because Amazon refunded my money for some unknown reason that had nothing to do with pirating."

Some are now investigating whether Amazon has the right to withdraw books that have been paid for. If the case does come to court, it could be very expensive for Amazon and may permanently sour relations with the Kindle community.