Authors affected by Amazon's contract dispute with publisher Hachette have started to band together against the online retailer, reported The New York Times on Thursday. More than 900 authors have signed a letter condemning Amazon for "using writers as hostages in its negotiations," referring to Amazon's choices to keep low stock of certain Hachette titles and taking weeks to ship them as the two companies battle over e-book prices.

The effort was spearheaded by 58-year-old Douglas Preston, a writer whose thrillers have been published by Hachette. Preston reports to the Times that Amazon has contacted him repeatedly, trying to get him to stop his campaign against the company and to see its side of the argument, but Preston will not be silenced.

Amazon has uncharacteristically tried to defend itself with forum posts over the last few weeks. First, the Books team stated that its decision to keep low Hachette stock is barely affecting its business, then it followed that up with a math-based argument for mandating that Hachette charge a lower cover price overall.

Preston's letter to Amazon asks readers to contact Amazon CEO Jeff Bezos directly and has been signed by writers including John Grisham, Stephen King, Tom Perrotta, Barbara Kingsolver, and Suzanne Collins. The letter is set to run as a full-page ad in the Sunday edition of the Times at a cost of $104,000, paid for by "a handful of the more successful writers," according to the Times.