Both the Justice Department and the Federal Trade Commission are aware of the new policy Apple implemented for media companies with applications in the App Store. The new terms state "that if an app offers customers the ability to purchase books outside of the app, the same option is also available to customers from within the app with in-app purchase."
A prime example is the Sony Reader app which was reportedly rejected from the App Store because its iOS app linked to its own digital store and did not use Apple's in-app purchase system to sell its eBooks. This new policy takes effect June 30 and will drive many purchases through the App Store, giving Apple a 30% cut.
U.S. regulators are taking a closer look at this policy to determine if it runs afoul of any federal antitrust laws. This interest is preliminary and may not turn into a formal investigation or sanctions against the company. The European Union is also closely monitoring this situation, but is currently not taking any action either.
Apple was under the microscope last year following its decision to ban iOS applications developed using third-party tools such as Adobe Flash. Both the FTC and the European Commission launched an investigation, but Apple reversed this policy before a decision could be made by either regulatory body.