Saturday 4 May 2013 13.22 BST
Are all telephone calls recorded and accessible to the US government?
"A former FBI counterterrorism agent claims on CNN that this is the case
Former FBI counterterrorism agent Tim Clemente, on CNN, discussing government's surveillance capabilities
The real capabilities and behavior of the US surveillance state are almost entirely unknown to the American public because, like most things of significance done by the US government, it operates behind an impenetrable wall of secrecy. But a seemingly spontaneous admission this week by a former FBI counterterrorism agent provides a rather startling acknowledgment of just how vast and invasive these surveillance activities are."