Case C-577/10: Judgment of the Court (Fourth Chamber) of 19 December 2012 — European Commission v Kingdom of Belgium (Failure of a Member State to fulfil obligations — Article 56 TFEU — Freedom to provide services — National legislation which imposes a prior declaration requirement on self-employed service providers established in other Member States — Criminal penalties — Obstacle to freedom to provide services — Objectively justified distinction — Overriding requirements in the public interest — Prevention of fraud — Protection against unfair competition — Protection of self-employed workers — Proportionality)