By the late 1990s the ECHELON system was capable of intercepting satellite transmissions , public switched telephone network ( PSTN ) communications ( including most Internet traffic ) , and transmissions carried by microwave . A detailed description of ECHELON was provided by New Zealand journalist Nicky Hager in his 1996 book " Secret Power " . While the existence of ECHELON was denied by some member governments , a report by a committee of the European Parliament in 2001 confirmed the program 's use and warned Europeans about its reach and effects . The European Parliament stated in its report that the term " ECHELON " was used in a number of contexts , but that the evidence presented indicated it was a signals intelligence collection system capable of interception and content inspection of telephone calls , fax , e-mail and other data traffic globally . The report to the European Parliament confirmed that this was a " global system for the interception of private and commercial communications . " In the aftermath of the September 11 attacks in 2001 on the World Trade Center and the Pentagon , the scope of domestic spying in the United States increased significantly . The bid to prevent future attacks of this scale led to the passage of the Patriot Act . Later acts include the Protect America Act ( which removes the warrant requirement for government surveillance of foreign targets ) and the FISA Amendments Act ( which relaxed some of the original FISA court requirements )
September 11 attacks
September 11 attacks
Origins of global surveillance