"Only Facebook Ireland can respond to your concerns." That is the response you are likely to get from Facebook if you accuse the world's biggest social network of breaching Europe's tough new laws on data privacy.

The company's European headquarters are in Ireland; data from its users in the region is officially controlled and processed there; and its lead supervisor is the Irish Data Protection Commission. This isn't a one-off: Google, Twitter, Microsoft and Apple all run their European operations from Ireland, drawn in part because of the country's low tax rates.