This report characterizes several observations, including counts of peers trafficking in CEM; the proportion of arrested traffickers that were identified during the investigation as committing contact sexual offenses against children; trends in the trafficking of sexual images of sadistic acts and infants or toddlers; the relationship between such content and contact offenders; and survival rates of CEM. In the 5 P2P networks examined, researchers estimated there were recently about 840,000 unique installations per month of P2P programs sharing CEM worldwide. Researchers estimate that about 3 in 10,000 Internet users worldwide were sharing CEM in a given month; rates vary per country. There was an overall month-to-month decline in trafficking of CEM during the study. By surveying law enforcement, the study determined that 9.5 percent of persons arrested for P2P-based CEM trafficking on the studied networks were identified during the investigation as having sexually offended against children offline. Rates per network varied, ranging from 8 percent of arrests for CEM trafficking on Gnutella to 21 percent on BitTorrent. Within BitTorrent, where law enforcement applied their own measure of content severity, the rate of contact offenses among peers sharing the most-severe CEM (29 percent) was higher than those sharing the least-severe CEM (15 percent). Although the persistence of CEM on the networks varied, it generally survived for long periods of time; e.g., BitTorrent CEM had a survival rate near 100 percent. (Publisher abstract modified)