NSA Prism program taps in to user data of Apple, Google and others

• Top-secret Prism program claims direct access to servers of firms including Google, Apple and Facebook
• Companies deny any knowledge of program in operation since 2007

• Obama orders US to draw up overseas target list for cyber-attacks

The National Security Agency has obtained direct access to the systems of Google, Facebook, Apple and other US internet giants, according to a top secret document obtained by the Guardian.

The NSA access is part of a previously undisclosed program called Prism,...