for its e-books. On April 11, 2012, the United States Department of Justice filed United States v. Apple Inc., naming Apple, Hachette, and four other major publishers as defendants. The suit alleged that they conspired to fix prices for e-books, and weaken Amazon.com's position in the market, in violation of antitrust law. In December 2013, a federal judge approved a settlement of the antitrust claims, in which Hachette and the other publishers paid into a fund that provided credits to customers who had overpaid for books due to the price-fixing. On June 28, 2013, Hachette announced it would acquire Hyperion Books from Disney Publishing Worldwide. On March 12, 2014, Hyperion was renamed Hachette Books, with the naming of Crown Archetype's editor-in-chief Mauro DiPreta as vice president and publisher. In May 2014, Amazon.com announced it was no longer taking pre-orders for Hachette books, stating a breakdown in negotiations over profit-sharing arrangements. According to Hachette, Amazon had also stopped discounting its books, sending prices of Hachette titles in the U.S. to more than twice what they were selling for in the UK. Amazon published a letter on August 10, 2014 asking authors and readers to email Hachette's CEO Michael Pietsch and ask for lower e-book prices. Pietsch reportedly replied to each message he received. In November 2014, Hachette announced that it had entered into an agreement to purchase nonfiction publisher Black Dog & Leventhal. The sale was finalized in January 2015, and Black Dog & Leventhal became an imprint of the Hachette Books publishing division. In June 2014, the company in conjunction with Ingram Content Group, and Perseus Books Group, announced a three-way deal whereby Hachette would buy Perseus and then sell that company's client services businesses to Ingram. Financial details of the deal were not disclosed. The deal was called off on August 7, 2014. On March 6, 2016, HBG announced that it had entered into a binding agreement to purchase the publishing division of The Perseus Books Group. Perseus's distribution business was sold to Ingram in a separate move. The sale was completed in April 2016, and the publishing business joined HBG as the Perseus Books publishing group. In April 2016, HBG announced an agreement to create a joint venture with the Yen Press imprint and Japanese publisher Kadokawa. Yen Press became known as Yen Press LLC, and is no longer considered an imprint of HBG's Orbit publishing division. On