The discussion so far has looked at systems and laws in place as of the year 2000. In the wake of the destruction of the World Trade Centre the "War on Terrorism" has included provisions for the increased use of surveillance technologies by world governments.
An example... The "Total Information Awareness" program as the Pentagon called it, attracted the attention of critics who saw it as an Orwellian assault on privacy with a vast potential for abuse.
The program aimed to uncover potential terrorists through the use of data profiling. That part of the plan involved the creation of a giant database holding credit card, travel, medical, school, and other records of (at first) every person in the United States.
To try to detect the activities of terrorist groups, the next part of the plan called for the development information systems that would sweep up data from the billions of electronic transactions that take place via the Internet.
http://en.wikipedia.org/wiki/Total_Information_Awareness
Of course with absolute power comes the absolute abuse of power...
http://www.wired.com/science/discoveries/news/2006/05/70908
In June 2013 Edward Snowden a contractor working for America's National Security Agency released information about the next generation of surviellance programs PRISM.