Why would Apple have agreed to pay higher prices for books while Amazon was still out there hocking them below cost? Good question. Those curious circumstances are why some, including Justice it now appears, think there might have been collusion on the part of the publishers. The European Commission opened its own formal investigation into the matter back in December.

If the regulators are right, and the big publishing houses really did get together with Apple to plot a price hike, it would seem to be a clear violation of antitrust law — old fashioned price-fixing conspiracies are the sort of corporate skullduggery that can get an executive tossed in jail.  —How Cheap Should Books Be?  (The Atlantic).