Snowden leaks: US and UK 'crack online encryption'
6 September 2013 Last updated at 15:41 BST
US and UK intelligence have reportedly cracked the encryption codes protecting the emails, banking and medical records of hundreds of millions of people.
Disclosures by leaker Edward Snowden allege the US National Security Agency (NSA) and the UK's GCHQ successfully decoded key online security protocols.
They suggest some internet companies provided the agencies backdoor access to their security systems.
The NSA is said to spend $250m (£160m) a year on the top-secret operation.
Gordon Correra looks at how much the government actually knows about us.