lines, perpetrators may set up websites with explicit content including pornography, and select URLs (uniform resource locators) that contain small or common misspellings of the names websites intended for use by children. Conversely, transmission of harmful material to children may be profitmotivated. For example, professional spam operations that send out millions of e-mails advertising pornography or other explicit content may simply not care about the harmful consequences of such material on children.184 Results vary widely on the link between non-contact child sexual abuse material offenders and contact abusers.185 Studies suggest, however, that at least some offenders commit both contact and non-contact offences.186 While the degree and details of such overlap remains the subject of significant debate,187 researchers have documented substantial overlap among criminal convict populations.188 Specifically, in one long-term study of offenders convicted for non-contact child sexual abuse material crimes, 85 per cent eventually disclosed that they also had committed undetected contact abuse.189 Other research suggests that investigating cases of child sexual abuse material possession often leads to arrests for child sexual abuse, corroborating the findings of self-disclosure research.190 Conversely, many perpetrators arrested for contact offences are found to possess significant collections of child sexual abuse material.191 Research also indicates that contact offenders have longer criminal records,192 more often have a history of child sexual abuse, and tend to use emotionally charged coping strategies when under stress.193 While contact offenders report high levels of previous sexual abuse, noncontact offenders report a more complex history of childhood problems associated with early childhood sexual experience and sequentially abusive adult sexual experience.194 One recent review concluded, for example, that: “[i]t is evident that there are differences between Internet and contact offenders related to demographic characteristics such as age, level of education, and measure of intelligence as well as psychological variables”.195 Most possessors of child sexual abuse material are preferential child sex offenders, or paedophiles,196 who use the material to nurture their sexual fantasies about children or as proof of their conquests in offender communities.197 Preferential child sex offence conduct is also linked to the commercial sexual abuse and exploitation of children in the travel and tourism industries.198 In a different category of offenders, families may exploit their own or other local children by producing sexual abuse material solely for profit. In some cases, a child may be made to stand naked in front of a webcam, and the family member may not even consider such behaviour to constitute sexual abuse or harm to the child.199 Caution must be exercised in interpreting conviction data. Overall reporting rates for child abuse are estimated at approximately one-third for girls and one quarter for boys. Only 5 per cent of victims in a 2011 United Kingdom study reported making a formal complaint to police. From this small percentage of reported victimization, only 7 per cent result in criminal convictions. Persons convicted thus correspond to a small, and not-necessarily representative sample of the whole population of sexual abusers; Joseph Sullivan, 2013. Commentary at the Informal Expert Group Meeting on the Effects of Information and Communication Technologies on the Abuse and Exploitation of Children. Vienna. September 23, 2013 through September 26, 2013. 193 Howitt, D., Sheldon, K., 2007. Pp. 139-172 194 Howitt, D., Sheldon, K., 2007. Pp. 123-160. 195 Quayle, E., Sinclair, R., An introduction to the problem. In Quayle, E., Ribisl, K. (eds.), 2012. Understanding and Preventing Online Sexual Exploitation of Children. P. 7. 196 Seto, M. C., 2010. 197 The Berkman Center for Internet & Society at Harvard University, 2008. P. 37. 198 ECPAT. End Child Prostitution, Child Pornography & Trafficking of Children for Sexual Purposes. Available at: http://www.ecpat.net/ faqs#child-sex-tourism. 199 See e.g. CEOP, 2013. Paragraph 24. 192 184 See, for example, OECD, 2011; House of Commons Culture, Media and Sport Committee, 2008. Harmful content on the Internet and in video games. Tenth Report of Session 2007–08. 185 See e.g. Bourke M. L., Hernández. A., 2009. “The Butner Study Redux”, Journal of Family Violence 24:183-191. 186 See, for example, Beech, et al., 2008. 187 See generally Neutze, J., et. al, 2010. “Predictors of child porngraphy offences and child sexual abuse in a community sample of paedophiles and hebophiles”, Sexual Abuse: A Journal of Research and Treatment 22(4):3-24. 188 Seto, M., 2010. “Child Pornography Use and Internet Solicitation in the Diagnosis of Pedophilia”, Archive of Sexual Behaviour 39:591–593. 189 Bourke M. L., Hernandez, A., 2009. 190 Wolak J., Finkelhor, D., Mitchell, K.J., Ybarra, M.L., 2008. 191 United Nations Human Rights Council, 2009. Report of the Special Rapporteur on the Sale of Children, Child Prostitution and Child sex abuse material [A/HRC/12/23]. Paragraph 42. II. Evaluating the problem  29