Is Carnivore based upon Etherpeek?
EtherPeek was certainly used originally for investigative work by the FBI. It probably is what the FBI called “Omnivore”. They would obtain court orders for all traffic to/from an IP address and save it directly to evidence files. EtherPeek supports this feature well whereas other commercial sniffers don’t do this as well. However, the FBI found EtherPeek too limiting, and created their own product based upon the sniffing subsystem created by PCAUSA (http://www.pcausa.com).