The suppliers come from Northern Europe and Japan, as well as the United States. In Internet chat rooms the cops often pose as young girls, hoping to lure suspects into sending material. Military officers, college professors, CEOs. To Daufenbach's surprise, bobby2vt was actually a veteran New York City cop. It is often harder to trace the origins of Internet-based porn than the paper versions.
Agents increasingly see cases in which one child's head is morphed onto another's body.
This can make it extremely difficult to identify the naked child most likely to have been abused. Another technique investigators face is known as steganography, the hiding of images within a larger file. Most daunting, say the cybercops, is the growing use of encryption, in which computer files are masked in codes. The illicit trade is especially hard to control because it is decentralized, with thousands of distributors around the world. Flores, who oversaw child-porn prosecutions at the Justice Department for three years, resigned in frustration last February.