Authors including Robert Harris, Joanne Harris and Jilly Cooper have condemned an app which allows users to cover up swear words in eBooks.
The newly-launched Clean Reader program hides all explicit and rude words in novels in eBook format and replaces them with tamer alternatives.
Chocolat novelist Joanne Harris has decried it as a form of censorship.
"Writers of fiction choose their words (including what you refer to as profanities) very carefully," she said in a scathing blog post.
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"To enable a writer's work to be modified without permission, then for you claim that nothing much has been altered, is to completely misunderstand the nature of fiction writing."
Robert Harris, who wrote the books behind films including Enigma and The Ghost Writer, told Britain's The Independent newspaper that he uses swear words "for a reason" and it's not "done lightly".
Cooper adds, "I would hate for someone to remove all the swear words in my books - they would lose their pulse... This app is ridiculously prudish, but hysterical at the same time."
The creators have defended themselves against the criticisms, insisting they are not censoring stories because the Clean Reader function can be turned on or off.