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…according to a former NSA employee, by 1995 the agency had installed sniffer software to collect various kinds of traffic at nine major Internet exchange points (IXPs). Terry Thompson, the NSA deputy director, also acknowledged in 2001 that the agency has taken to hiring technicians away from the private companies that run much of the World Wide Web, such as Cisco systems, and employing them to reverse engineer various communications technologies in order to locate vulnerabilities that the agency can exploit. This poached taken much be invaluable in sorting through the packetized and multiplexed flows of digital data.

* Patrick Radden Keefe, Chatter: Dispatches from the Secret World of Global Eavesdropping