Cyberbullying involves threatening, harassing, or embarrassing someone using the internet or mobile devices. It most often occurs on social media sites and through messages. Between 10-40% of young people experience cyberbullying. It is a major problem because 95% of teens in the US are online. To prevent cyberbullying, it is important to report incidents, block cyberbullies, and have open communication between parents and children about internet use. Schools and social media sites also work to address cyberbullying through support systems and policies against online harassment.