This document is a chapter of "Protecting children from sexual violence - A comprehensive approach", published as part of the Council of Europe campaign to stop sexual violence against children. The publication aims at inspiring judges, the police, educators, governments, the media and legislatures to join the campaign and expose, demythify and take concerted action to combat sexual violence against children, a phenomenon that affects as many as 20% of children in Europe. Publication "Protecting children from sexual violence - A comprehensive approach". Available online at: www.coe.int/t/dg3/children/1in5/WhatWeKnow/Publication_en.asp