It can only share a certain amount under EU Law. There would have to be some sort of criminal threat.
Is there any check/balance on the definition of "criminal threat"? Because that's a pretty loose definition a priori.
"We believe a terrorist exists in GB. That constitutes a criminal threat. To catch him or her, we need to run big data analysis on all communications."
That doesn't follow - that wouldn't allow the export of European data to the US.