Carnivore, also called DCS1000, controversial software surveillance system that was developed by the U.S. Federal Bureau of Investigation (FBI), which used the system to search the e-mail and other Internet
activity of identified criminal suspects during investigations circa
2000–02. The system—which some claim became controversial mainly for its
name rather than for its capabilities—came under fire from opponents
ranging from the liberal-leaning American Civil Liberties Union to staunchly conservative U.S. senators, all of whom were worried that the technology could be used to spy on the public.