A former National Security Agency (NSA) official has claimed that the agency's phone data collection of all US Verizon customers is only a 'tip of the iceberg' as the estimates go as high as 20 trillion phone calls and mails by US citizens.
According to the Washington Times, William Binney has revealed that the collection can be traced back to the days of domestic surveillance following the attacks on September 11.
Binney confirmed that the data collection took place under a highly classified NSA program code-named 'Stellar Wind' which was a part of the Terrorist Surveillance Program launched on the then US President George W. Bush's orders.
Binney who has worked with the agency for more than 30 years said that he believes NSA has been collecting data since October 2001 and makes for over a billion calls daily.
According to the report, the Foreign Intelligence Surveillance Act (FISA) court order had earlier directed Verizon to hand over 'metadata' about every call made or received by all its US customers that included both the calling and receiving phone numbers, the time of day and length of the call and the whereabouts of the two parties.
The report said that although Democrats and Republicans on the congressional intelligence committees asserted that the wide-scale collection of phone data had enabled authorities to disrupt at least one terrorist attack, professor Stephen B. Wicker has claimed that the line between content and context is being constantly blurred because of the GPS features in mobile phones and other technological advances.
Federal courts have meanwhile held that metadata which includes information about the location of mobile phones, is not covered by the warrant requirements of the US Constitution, the report added.