The Department of Justice sues pretty much everybody over e-book price fixing

The DoJ doesn't play when it comes to price fixing!

2012 was a bad year for e-book publishers, who saw one of their chances to break Amazon’s stranglehold on the market slip away. Afraid that Amazon was driving e-book prices too low, the publishers allegedly collaborated—conspired, you might say—to push wide adoption of an "agency" model, where the publishers set the price of e-books and retailers received a cut of the profits.
Apple allegedly encouraged the move, wanting to secure higher 30 percent margins on e-book sales rather than being forced to lower prices with competitors like Amazon, who were all too willing to offer e-books at lower prices (and lower margins). Under agency pricing, the cost of best-selling e-books leaped from Amazon's early $9.99 selling price to between $12.99 and $14.99
The Department of Justice was none too fond of this “collective effort to end retail price competition by coordinating their transition to an agency model across all retailers,” which would assuredly result in higher prices for consumers. The DoJ filed suit against 5 major publishers, as well as Apple, who was accused of colluding with the publishers out of a desire to raise profit margins on e-books. HarperCollins, Simon & Schuster and Hachette agreed to settle right away, while Penguin agreed to the DoJ's terms in December. Apple and Macmillian continue to fight the case in court.