Cyberbullying
Cyberbullying is very bad. Don't do it. Cyberbullying is the intentional harassment of another person using online technology to attack, harass, or bully someone. Cyberbullying attacks have become increasingly more common in today's day and age and are entirely inappropriate. The harming of another person, whether physical or psychological, is wrong and words hurt the same when said aloud as when sent via text, email, screenshot, video call, chat rooms, etc, etc.
To learn more about cyberbullying, go here.