The accusation being that they have colluded for Price Fixing.
The Justice Department has warned Apple Inc. and five of the biggest U.S. publishers that it plans to sue them for allegedly colluding to raise the price of electronic books, according to people familiar with the matter.
Steve Job's autobiography is apparently amongst the most damning evidence
"We told the publishers, 'We'll go to the agency model, where you set the price, and we get our 30%, and yes, the customer pays a little more, but that's what you want anyway,'" Mr. Jobs was quoted as saying by his biographer, Walter Isaacson.
The publishers were then able to impose the same model across the industry, Mr. Jobs told Mr. Isaacson. "They went to Amazon and said, 'You're going to sign an agency contract or we're not going to give you the books,' " Mr. Jobs said.