Strategies for neutralising sexually explicit language George R. S. Weir and Ana-Maria Duta Department of Computer and Information Sciences University of Strathclyde Glasgow, UK e-mail: [email protected] Abstract — While scales for the ‘strength’ of pornographic images have been developed and used in research and for Whilst children can make themselves vulnerable in judicial purposes, the potential emotive impact of text-based relation to their online behaviour it is equally the pornography has received little attention. In this paper we case that offenders target and exploit this describe our approach to characterising dimensions of sexually vulnerability. CEOP sees frequent grooming explicit language and outline their use in strategies for behaviour targeted towards children and social neutralising such language. Our intended application of this networking sites are the most commonly reported work is contexts where we may wish to affect the content to environment in which this activity takes place. This which a student, trainee or other professional may be exposed. By controlling the quantity and degree of such content, we aim to is likely to be due to the ease with which minimise any detrimental effects (observer impact) that such individuals can create profiles on such sites. [4, p.7] content may have on ill-prepared individuals. Through such networking sites, criminals may seek to Keywords- sexually explicit text; dimensions of sexual language; develop a relationship with one or more minors as part of the neutralising emotive force grooming process toward child exploitation. I. INTRODUCTION Criminals use a number of methods to build Exposure to hard-core pornography in the form of friendships with children on social networking explicit images and video is often a necessary aspect of the sites. Once a relationship is formed the offender professional's role in digital forensics, law enforcement or will use their position to initiate some form of legal representation. In presenting court evidence that sexually exploitative activity”. (op. cit.) includes paedophile imagery, a common strategy is to register the 'strength' of each item as a shorthand record of In such settings, the content may be entirely (or largely) the content and as a means of conveying the seriousness of text-based and the collation of evidence against an offender any offence. In Europe, the COPINE (Combating will require the assembly and annotation of such computer- Paedophile Information Networks in Europe) classification based interactions. As in the graphic image setting noted model is often used [1]. This model, conceived as an aid both earlier, we have several contexts in which exposure to to research and criminal proceedings, categorises the severity explicit materials may be a professional requirement - as a of victimisation in child pornography on a ten point scale [2]. digital forensic investigator, a legal professional or a member Based on the COPINE classification, the Sentencing Advisor of law enforcement. Panel of the UK’s judiciary developed the five point SAP In the present paper, our application domain is the range scale for use in court cases [3]. of professional contexts in which individuals may be Clearly, a primary motivation behind such an approach is exposed to sexually explicit content, but content that is text- the need to provide a standard for gauging the seriousness of based rather than image-based. Our purpose is to explore the offences. A further motivation is a desire to limit the need to possibility of developing techniques, based upon the expose individuals to potentially distressing or damaging classification of such textual content, which will provide materials. Thereby, an outline description of the means to neutralise by varying degrees, the content to which classification scheme, added to a COPINE or SAP measure a student, trainee or other professional may be exposed. This of the materials in a suspect's possession, can convey one purpose is motivated by a desire to control the quantity and significant dimension in a criminal case, i.e., the degree or degree of such content in the hope of minimising any 'strength' of any individual image or video content. (A detrimental effects (observer impact) that such content may second significant dimension will be the quantity of have on ill-prepared individuals. Given that such raw materials that fall under each classification.) material may be highly sexualised and explicit, we see such a One major area of concern for law enforcement is the use development as a component in the duty of care toward of social networking and similar chat-based sites for the professionals early in a career who may ultimately require sexual grooming of minors. According to the Child first-hand exposure to sexually explicit or paedophilic Exploitation and Online Protection (CEOP) Centre, materials. II. AN EASY SOLUTION ? unlikely to be the case for textual materials. (Of course, this If our objective was purely evidential, then there would will depend upon the prevailing detail of the obscene appear to be an easy solution to the classification of such publications act.) The offence more commonly committed in text-based materials. Having derived the content from a a text-based child interaction setting is that of grooming. suspect’s on-line interactions with a child, we might apply Significantly, images have no required role in establishing the existing COPINE or SAP classification. Let us consider grooming behaviour. Rather, grooming would be this prospect with reference to the SAP categories [5] listed determined by the record of interaction between the groomer in Table 1. and the target child. A distinctive feature of text content over images is that the mood, attitude and intentions of an TABLE I. SAP IMAGE CLASSIFICATION offender may be apparent from the content of text-based interaction in a fashion that could not be matched by mere 1. Images depicting nudity or erotic posing with no sexual activity possession of extreme imagery. 2. Sexual activity between children, or solo masturbation by a child 3. Non-penetrative sexual activity between adult(s) and child(ren) One further point confirms the need to step beyond a 4. Penetrative sexual activity between child(ren) and adult(s) SAP or COPINE classification for text content. Put simply, 5. Sadism or bestiality while the incidence of grooming may be disconcertingly high, the incidence of paedophiles providing a factual textual These five categories of paedophile images present a record of their child exploitation activities will be very low. clear ranking of content severity and, if we ignore the Thereby, a SAP or COPINE category will rarely be usefully explicit reference to images in the first category, the applicable in cases of text-based materials. Possession of descriptors could be applied to texts. For instance, a textual accounts that meet such categories will not itself paedophile may have a blog that records exploits with constitute proof of deed. Neither will such classifications children and such activity as described in the blog may map assist in the identification of grooming activity. directly to one or more categories in the SAP classification. There is concern in many quarters about the incidence of While such text contexts may allow the evidential use of the adult grooming of vulnerable minors through communication SAP categories, one characteristic of this classification is the channels such as social media, chat rooms and email. presumption of reality . Indeed, many law enforcement agencies are devoting energy When dealing with images, there is reasonable assurance to proactive monitoring of chat forums used by young that they represent real events that have actually taken place. people, in order to detect, track and prevent child sexual Indeed, as a step toward prevention of further exploitation, exploitation. In this section, we have argued that a content law enforcement agencies exert considerable energy in classification model such as SAP or COPINE is not suited to attempting to identify children from their appearance in text-based materials paedophile images. So, the evidential application of such image classification schemes relies upon this assumption that III. REDUCING OBSERVER IMPACT the content so described represents real events. Another way The clear overlap between our objective and the use of of expressing this point is that the primary evidential basis of image classifications (such as COPINE and SAP), is the such imagery is its role as proof that offences have been presumption that exposure to explicit materials may be committed. The SAP categories can equally apply to harmful to an individual. While this may not be the case for ‘fabricated’ images in which no real children are represented every individual who has such exposure, many will be or exploited. In such cases, possession of these images may distressed or (at least) embarrassed when confronted by serve a secondary evidential basis toward establishing the sexually explicit content. This is all the more likely in a character or inclination of a suspect, but since they would not professional context in which the individual is aware that be tied to any real event, they are not evidence of child others (including peers and superiors) are aware of the exploitation. situation. For want of a better term, we have called this The presumption of reality is less strong when dealing effect ‘observer impact’, with the idea that the content to with textual descriptions of events. This is why we often which the individual is exposed may have more or less have to suspend disbelief when reading novels or listening to emotive force and associated discomfort, distress or damage radio plays. Of course, textual accounts (like verbal to the observer. accounts) may provide corroborative evidence that can be As noted above, in some contexts image classification tied to other sources and known events, e.g., through the schemes can reduce the observer impact by eliminating the presence of precise details that are unlikely to be known by need to observe the raw content.