A unique aspect of cyberbullying that has been frequently discussed and researched is the involved media. For example, Smith et al. categorized cyberbullying according to seven different media or communication tools because " different media have different characteristics": Text messages, emails, phone calls , photo or video clips, instant massager, website, and chat rooms. Research showed that different media were indeed used with different frequentcies for cyberbullying and had different effects on cyber-victims'experience of cyberbullying. However, the most frequently used tools for cyberbullying vary across studies. Whereas Smith et al. found most cyber-bullies used phone calls; Slonje and Smith found most cyber-bullies used emails. Additionally, Smith and colleagues demonstrated that adolescents consider cyberbullying by photo or video clips to be more distressing than conventional bullying, and cyberbullying by all other media less distressing than conventional bullying.