This MA thesis in Social Work deals with digital sex offence among children and young people and how social work can contribute to preventing it. We have chosen a phenomenological point of departure that we wish to apply to the collection and analysis of data; the thesis is induction-based. The issue is that children and young people get social problems both when committing digital sex offence and when being victims of such, and that this is an increasing problem. At the societal level much is known about prevention and aftercare of digital sex offence, but the knowledge is fragmented, which hampers efficient prevention of the problem. We have chosen a methodological point of departure in a phenomenological approach, and accordingly we have been interested in examining the subjective life world of our informants. Our analyses have shown that claims in society have an effect on how social work is facilitated in preventive work or in aftercare. We have found that lack of knowledge has consequences for whether children and young people know the boundaries and legislation in the digitalized world, and that they use neutralization techniques in order to legitimize their deviating behaviour – rarely on purpose, however, but rather due to lack of adult control. It has also become clear that there is a difference between the behaviour of boys and girls on the internet. It turns out that girls are more exposed due to the fact that they should know better. Moreover, children and young people do not always involve their parents in their online lives and do not see the parents as protectors. It is also of importance that teachers and employees in the “SSP” (collaboration between social authorities, school and police) play a decisive role in the prevention process. Our conclusion includes an outline of a suggestion of how to reorganize social work in a way where we do not lose children and young people in an increasingly digital world.