BBC News – Computer virus tackles child porn An ingenious attempt to use viruses to serve humanity instead of irritating it. It searches infected computers for suspicious image files and sends a directory listing to one of several authorities around the world, but no law enforcement organization is going to be too happy about receiving a deluge of email much of which will be false alarms.
Also, this depends on a child porn user opening an attachment on an email message with the subject “Help us all to end illegal child porn now” – hardly likely!