Pedophiles have learned to use the latest photographic, computer, and telecommunications technology to avoid traditional law enforcement methods for detecting child pornography and child sexual exploitation. Child pornography sent through the mail and through customs is declining, as the Internet sends photographs from users in one country to those in another country with little risk of detection. Further, Internet "chat rooms" provide the opportunity for pedophiles to communicate with and lure potential victims into face-to-face contact. Although Internet and computer-related criminal activity can leave evidence in the user's computer, there are now high-tech means for instantly wiping out a computer's contents even through voice commands. Investigations of these crimes can succeed, however, through international cooperation centered in Interpol, carefully timed raids on suspects' computers, and various types of "sting" operations. Also, a broadly worded search warrant can yield physical evidence unrelated to computer transmissions, such as photographs and lists of names, addresses, and telephone number of other pedophiles. Some pedophiles also keep written accounts of their contacts with victims. Through training, law enforcement officers can become more proficient at working the Internet for leads and exploiting leads derived from local investigations.