Net bullying

Recently, the net bullying exists. I did not know it. The victim doesn't know assailant's name in the net. Then, the assailants write abuse. Slandered word remains in shape in the net bullying. The victim keeps being afflicted by it. And he third party doesn't discover it easily. There was bullying for a long time. But I think this bullying is very malignant. We should consider victim's feelings. Why does not the assailant think that bullying is uncouth? But when the victim is bullied, can I be correct?