The customers of the Dutch cloud-services conpany I work for haven been demanding this for at least ten years. Snowden didn't change much there, it's been going on since the Patriot act. European Union privacy legislation demands that sensitive data is stored within the EU. Storing data in other countries is only permitted if a satisfactory level of protection can be offered. This was used in marketing by EU companies in order to promote their own services, effectively creating FUD around US-based services.

When the Amsterdam Internet Exchange (AMS-IX) recently opened up an office in NYC there was a big fuss about it, because it would make the entire Dutch internet traffic subject to the Patriot act, since it applies to any company with an office on American soil.