Edward Snowden, the whistleblower behind last month’s massive leak of classified documents from the National Security Agency, is currently sitting in a Moscow airport unable to leave, a man without a country. This choice, Snowden claims, he made gladly: “I can’t in good conscience allow the U.S. government to destroy privacy, internet freedom and basic liberties for people around the world with this massive surveillance machine they’re secretly building.” While a number of South American countries, including Venezuela and Bolivia, have offered him asylum, his safety is far from assured; U.S. officials have promised that accepting Snowden will put any of these countries “directly against the United States.”
The most troubling project Snowden unveiled is officially designated US-984Xn but has become more widely known by its government code name, PRISM. His leaked slides indicate that PRISM grants the NSA direct access to the data of several of the Internet’s most popular services, including Facebook, Google, Yahoo and Skype. Although the law that authorized the program mandated that surveillance targets be identified “with 51 percent certainty” as foreign nationals located outside the US, subsequent court orders have authorized the NSA to use “inadvertently acquired” information about US citizens, and the leaked slides state that targeting domestic citizens is “nothing to worry about.”
Technology experts have hypothesized that PRISM most likely operates by wiretapping Tier 1 network providers, companies like AT&T and Verizon who provide the majority of Internet infrastructure. Large Internet services such as Facebook are connected directly to Tier 1 networks through pieces of hardware called edge devices, which allow them to form “peering connections” with Internet service providers. These connections reduce the number of networks across which data must travel, decreasing the latency or “lag” a user experiences when connecting to a large site. By placing a physical tap on the wires between a company’s edge devices and the Tier 1 network, the NSA could “view and copy data transmitted over every single session from a user to an application in realtime.”
All of this massive amount of data must be stored, and it is thought that an NSA facility being constructed in Utah is location for that storage. Although the task seems daunting, mass storage is surprisingly inexpensive: by one estimate, all of the phone calls made in America over the course of a year could be captured in a warehouse of less than 5,000 square feet, at a cost of approximately $27 million. Storage capacity is actually becoming more affordable more quickly than computing power; the growth patterns of the two are estimated by Kryder’s Law and Moore’s Law, respectively. Phenomena such as giant magnetoresistance can be exploited to pack more data onto ever smaller surfaces.
The NSA undoubtedly has the technological means to capture a significant portion of the traffic that passes through the Internet on a daily basis. Any restrictions to this capacity therefore must come from the legal sphere, and it appears that both Congress and the Foreign Intelligence Surveillance Court are granting the agency considerable leeway in its operations. PRISM provides a powerful tool, one that can be used to protect the nation or abused to place pressure on citizens with unpopular views. It is the responsibility of the government to ensure that this technology does not stifle the free expression and dialogue of ideas from which progress must arise.