The diploma thesis called " Cyber - bullying in Society" deals with this phenomenon and there Ialso mentioned its related problems such as cyberstallking, luring, video clips, where agressors torture thein victims. My aim is to inform the public with this topical phenomenon.I focus on its types, who the attacker is in these forms of bullying nad who becomes a victim. Additionally, I describe the divisor of cyber-aggresors, the effects on cyber.bullying victims and how the victims can be helped. In the practical part I analyse a case study of a girl, who I met and who became a cyber-bullying victim. I also describe the offender of this crime, I try to define with the help of a professional the investigatoin and subsequent capture of the cyber-aggresor by Czech police. Furthemore I džine the specific development of cyber-bullying in a sekond case and steps taken by the girl's school in order to capture cyber-aggresors and subsequently punisch them. From the analysis case studies I learned that she was tiny and at last kyberšikanována girl Hana (14 ), pupil one Prague ZŠ. The girl was in school the new, because she's out of the original school, to which she didn't like and she was in her bad favor. The girl came from adverse family environment, in which she lived with her mother, stepfather and...