The goal of this study was to explore how victims of cyberbullying perceive online aggressive attacks and when they see them as harmful. Interviews were carried out with 16 cybervictimised participants aged 15-17 years. The findings showed differences in the perception of online victimisation when perpetrated by an anonymous Internet user versus by a known person from the real world. The tendency of unknown online aggressors to threaten to hurt their victims offline increased the victims' feelings of harm. Where cyberbullying interconnected with the school environment, the feeling of harm was intensified by collective perpetration, and by onlookers being personally identifiable. Where cyberbullying was a part of traditional bullying, online victimisation being discussed at school reproduced the bullying and thus the trauma. The results showed that the link between cyberbullying and the physical environment is significant with respect to the victim's perception of its severity. (Contains 1 table.)