Cyber bullying involves bullying someone online, usually someone the bully knows personally like classmates. It can take different forms for males like sexual harassment or threats of physical harm, and for females like spreading rumors or purposely excluding someone. Cyber bullying can have negative effects on victims' self-esteem, mental health, grades and social life by causing depression, anxiety, loneliness and withdrawing from peers. It is carried out through methods like texts, social media, email and chat rooms. Prevention involves telling trusted adults and friends, avoiding the internet, and blocking bullies online. Policy makers need to take steps to address cyber bullying in schools and online.