Sim card database hack gave US and UK spies access to billions of cellphones

American and British spies hacked into the world’s largest sim card manufacturer in a move that gave them unfettered access to billions of cellphones around the globe and looks set to spark another international row into overreach by espionage agencies. 

The National Security Agency (NSA) and its British equivalent GCHQ hacked into Gemalto, a Netherlands sim card manufacturer, stealing encryption keys that allowed them to secretly monitor both voice calls and data, according to documents newly released by NSA whistleblower Edward Snowden.