Carnivore is software designed to get at "the meat" of sought-after information. FBI agents take an off-the-shelf PC with the software on it directly to the offices of an Internet service provider (ISP). There, they leave it in a locked cage, typically for about 45 days, making daily visits to retrieve captured data — the e-mails sent to or from a suspect. 

Like the more common phone tap, such an Internet tap must be authorized by court order. 

However, critics say Carnivore gives the Feds access to private information that exceeds those court order. In theory, it could process all the e-mail that passes through the ISP — not just messages sent to or from the suspect. 

Critics compare the software's activity to snooping on all the phones in a neighborhood to zero in on one phone. Others claim Carnivore goes beyond e-mail surveillance to also monitor overall Internet usage. 

Carnivore is only the beginning of cyber-surveillance for the FBI. The bureau intends to continue to upgrade its surveillance technology in order to keep up with criminal activity. 

For example, the current Carnivore system merely stores the data, while two other programs — "Packeteer" and "Coolminer" — process and display the information. Plans for newer versions of Carnivore that are under development include features to display captured Internet data as soon as it is intercepted.