cyber bullying

Cyberbullying is defined in legal glossaries as

• actions that use information and communication technologies to support deliberate, repeated, and hostile behavior by an individual or group, that is intended to harm another or others.
• use of communication technologies for the intention of harming another person
• use of internet service and mobile technologies such as web pages and discussion groups as well as instant messaging or SMS text messaging with the intention of harming another person.

Examples of what constitutes cyberbullying include communications that seek to intimidate, control, manipulate, put down, falsely discredit, or humiliate the recipient. The actions are deliberate, repeated, and hostile behavior intended to harm another. Cyberbullying has been defined by The National Crime Prevention Council: “When the Internet, cell phones or other devices are used to send or post text or images intended to hurt or embarrass another person."
A cyberbully may be a person whom the target knows or an online stranger. A cyberbully may be anonymous and may solicit involvement of other people online who do not even know the target. This is known as a 'digital pile-on.

source: Wikipedia