In 2000, the Federal Bureau of Investigation began using a program known as the Carnivore Surveillance Tool. The program essentially acted as a wiretap on certain users email accounts and different types of communications completed over the Internet. Carnivore works by monitoring the traffic of a specific user identified by the FBI. The program was originally approved by Janet Reno as Attorney General, though the government has remained quiet about the specifications of the program.
The Carnivore system relies heavily on the cooperation of internet service providers. The system itself works on an outside computer that must be installed at the ISP office. Once installed it uses a packet-sniffing software program to trace emails sent and received by the targeted user. The program sifts through all the emails and conversations and records the data on a removable hard drive. In some cases the program can be setup to look for certain words or phrases.
There have been cases in the past where the ISP refused to allow the Carnivore Surveillance Tool to be used on their system. In these situations, the FBI went to the Federal Court and received an official court order to resolve the issue. The FBI must also get a court order or warrant to use the tool. This must name a specific person or email address before the account is traced. Though the program filters all emails sent through that ISP, it only records those associated with the name or email address used in the warrant.
The roots of Carnivore were planted in the late 1990s when the FBI used a similar program known as Omnivore. This was later changed to Carnivore and then DCS1000. The program sniffed packets of information, gathered those packets together and analyzed them for the FBI. In 2005 the FBI discontinued the use of Carnivore.
A short history of the Carnivore program, as well as information about the name change, was published at Cnet News in 2001. A longer history of the project, including information on how it affects personal privacy is found on Hohonu: A Journal of Academic Writing. Author Eric Small delves into the project to tackle the issues that eventually made Carnivore obsolete.
The American Patriot Friends Network offers an unusual look at the program. They’ve included official records and documents relating to the program, including budget briefs and the costs associated with running the program. PC World takes a different approach, examining the end of the program and what that meant to the FBI.
Security Focus listed the details released by the FBI after the program ended, while they also listed information on the retirement at FBI Retires Carnivore.
More information on Carnivore and the fundamentals of how the program worked are available at Carnivore Surveillance System, Carnivore Diagnostic Tool, Carnivore/DCS1000, and Carnivore. These websites offer an in depth analysis of how the program worked, why the FBI ceased using the program and the results the system found.