When doing business in the EU, Whatsapp and whatnot will have to abide by EU legislation, including EU data protection rules, EU consumer legislation and national rules on entering into and interpreting terms and conditions and other contracts.

Data may be used only for the purpose it was collected and transfer to other legal entities require consent. In May 2018, the data orotection regulation ebters into force and the mandatory rules will be even tougher.

Maybe one day one or more of those companies will even have to pay a bit of tax in the EU.