The ECJ has ruled that industrial action designed to restrict an employer's freedom of establishment is unlawful unless the action is justified by an overriding reason of public interest (eg, the protection of workers) and is an appropriate and necessary means of achieving that objective. The case concerned industrial action aimed at dissuading a Finnish ferry company from reflagging one of its ferries in Estonia and replacing its Finnish crew with an Estonian one. (International Transport Workers Federation v Viking, ECJ)