The world’s biggest bookstore is a bit smaller these days.

Amazon’s secret campaign to discourage customers from buying books by Hachette, one of the big New York publishers, burst into the open on Friday.

The uneasy relationship between the retailer and the writing community, which needs Amazon but fears its power, immediately soured as authors took to Twitter to denounce what they saw as bullying.

Among Amazon’s tactics against Hachette, some of which it has been employing for months, are charging more for its books and suggesting that readers might enjoy instead a book from another author. If customers for some reason persist and buy a Hachette book anyway, Amazon is saying it will take weeks to deliver it.

The scorched-earth tactics arose out of failed contract negotiations. Amazon was seeking better terms, Hachette was balking, so Amazon began cutting it off. Writers from Malcolm Gladwell to J. D. Salinger are affected, although some Hachette authors were unscathed.