Case T-496/11: Judgment of the General Court of 4 March 2015 — United Kingdom v ECB (Economic and monetary policy — ECB — Action for annulment — Eurosystem Oversight Policy Framework — Challengeable act — Admissibility — Oversight of payment and securities settlement systems — Application to central counterparty clearing systems of a requirement to be located in a Member State party to the Eurosystem — Competence of the ECB)