Were Cell Phone Sim Cards Hacked by NSA and GCHQ?

"...a story published Thursday by The Intercept claims that a joint unit of spies from the US's National Security Agency and the UK's Government Communications Headquarters, or GCHQ, hacked into the internal network of Gemalto and stole the encryption keys used to secure the company's SIM cards. If true, that means the agencies would've been able to access personal data and tap into mobile phone voice and data communications from users around the world."  (Editor's pick)