title: Characterization of contact offenders and child exploitation material trafficking on five peer-to-peer networks.
abstract: We provide detailed measurement of the illegal trade in child exploitation material (CEM, also known as child pornography) from mid-2011 through 2014 on five popular peer-to-peer (P2P) file sharing networks. We characterize several observations: 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 we examined, we estimate there were recently about 840,000 unique installations per month of P2P programs sharing CEM worldwide. We estimate that about 3 in 10,000 Internet users worldwide were sharing CEM in a given month; rates vary per country. We found an overall month-to-month decline in trafficking of CEM during our study. By surveying law enforcement we determined that 9.5% 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% of arrests for CEM trafficking on Gnutella to 21% 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%) was higher than those sharing the least-severe CEM (15%). 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%.
authors.affiliation: College of Information & Computer Sciences, Univ. of Massachusetts Amherst, USA.
authors.forename: George
authors.initials: G
authors.lastname: Bissias
authors.affiliation: College of Information & Computer Sciences, Univ. of Massachusetts Amherst, USA.
authors.forename: Brian
authors.initials: B
authors.lastname: Levine
authors.affiliation: College of Information & Computer Sciences, Univ. of Massachusetts Amherst, USA.
authors.forename: Marc
authors.initials: M
authors.lastname: Liberatore
authors.affiliation: College of Information & Computer Sciences, Univ. of Massachusetts Amherst, USA.
authors.forename: Brian
authors.initials: B
authors.lastname: Lynn
authors.affiliation: College of Information & Computer Sciences, Univ. of Massachusetts Amherst, USA.
authors.forename: Juston
authors.initials: J
authors.lastname: Moore
authors.affiliation: College of Information & Computer Sciences, Univ. of Massachusetts Amherst, USA; Microsoft Research New York City, USA.
authors.forename: Hanna
authors.initials: H
authors.lastname: Wallach
authors.affiliation: Crimes Against Children Research Center, University of New Hampshire, USA.
authors.forename: Janis
authors.initials: J
authors.lastname: Wolak
mesh_terms: D002648:Child; D002650:Child Abuse, Sexual / Q000331:legislation & jurisprudence / Q000706:statistics & numerical data*; D057237:Criminals / Q000331:legislation & jurisprudence / Q000706:statistics & numerical data; D004882:Erotica; D064410:Human Trafficking / Q000331:legislation & jurisprudence / Q000706:statistics & numerical data*; D006801:Humans; D020407:Internet / Q000331:legislation & jurisprudence / Q000706:statistics & numerical data*; D010379:Peer Group; D060756:Social Networking
keywords: Child pornography; Child sexual exploitation; Internet; Peer-to-peer