Cyberbullying involves using technology to deliberately harm or harass others. Over half of adolescents have experienced cyberbullying. Factors that may contribute to a teen becoming a cyberbully include lack of parental supervision, drug and alcohol use, and family conflicts. Two teenagers who died by suicide after experiencing severe cyberbullying were Ryan Halligan in 2003 and Tyler Clementi in 2010. Cyberbullying can have negative effects on victims' self-esteem, grades, health, and risk of suicide. Educating kids, monitoring their online activity, and having them tell trusted adults about cyberbullying are ways to help prevent it.