Does US have right to data on overseas servers? We’re about to find out
Found on Ars Technica on Sunday, 25 June 2017

The Justice Department on Friday petitioned the US Supreme Court to step into an international legal thicket, one that asks whether US search warrants extend to data stored on foreign servers. The US government says it has the legal right, with a valid court warrant, to reach into the world's servers with the assistance of the tech sector, no matter where the data is stored.
In a nutshell, the US government claims it should not matter where the data is stored. What matters is whether the company can access that data in the US.
As long as the servers are within US borders, the government can have access. Outside the borders, it can not (unless they are maybe on embassy grounds). The US does no own the world.