For most people across the world the availability of the Internet and, in particular, hand-held devices, has had a positive impact on the way that people interact with the world and each other. However, this has also been associated with a number of cybercrimes and the focus of this chapter is online child sexual exploitation and abuse (OCSEA). These crimes include the production, preparation, consumption, sharing, dissemination or possession of CSEM and the solicitation of children for sexual purposes (sometimes called ‘grooming’), whether or not it results, or is intended to result, in a contact offence. It is difficult to make meaningful estimates of the scale of these crimes as conviction data is dependent on an individual being identified and the capacity of law enforcement to analyse the digital data associated with the crime. However, converging data would suggest that these crimes are increasing. OCSEA crimes may take place within a specific country but national and international cross-disciplinary collaboration is needed to both identify, locate and safeguard victims and prevent, investigate and prosecute these crimes. Europe is one region that has given greatest consideration to the issue of child exploitation and in particular child sexual abuse materials. In the last twenty years there has been considerable progress in understanding the demographic profiles of people who commit OCSEA crimes, what motivates them to offend and how they may be assessed in relation to future risks, particularly the commission of contact offences. However, it is unclear why our existing data would suggest that both identified OCSEA offenders and victims are more likely to be White rather than representing country-specific population demographics.