Case C-89/08 P: Judgment of the Court (Grand Chamber) of 2 December 2009 — European Commission v Ireland, French Republic, Italian Republic, Eurallumina SpA, Aughinish Alumina Ltd (Appeal — State aid — Exemption from excise duty on mineral oils — Regulation (EC) No 659/1999 — Article 1(b)(v) — Failure to state reasons — Court acting of its own motion — Plea involving a matter of public policy raised by the Community judicature — Infringement of the rule that the parties should be heard — Scope of the obligation to state reasons)