By studying the fulfilment of the EU data protection standards, we can reflect upon the sacrifices made for the benefit of a smooth interstate – member state or third state – cooperation and possible missed opportunities. Most significantly we will be able to conclude whether or not the time and efforts made to establishsolid EU data protection standards, can be considered as valuable or not in view of recent developments and in view of the cooperation with the US as a third state. In this contribution, the standards the EU has implemented regarding the protection of personal data, in particular the purpose limitation principle, will be analysed in the context of cooperation between the EU and the US police and judicial authorities in criminal matters. Finally, the question whether the EU complies with its own data protection standard of purpose limitation, will be answered.