The misuse of the Internet that takes advantage of adolescents and young adults' lack of understanding along with their growing online presence has left them at risk. A study comprising 1,092 South Korean high school students investigated ways in which adolescents and young adults may be exploited while engaged in popular and everyday online activities. Specifically, exposure to sexually explicit material (SEM) and violent content, cyberbullying, malware, phishing, and identity theft were examined in the contexts of social media, streaming movies and/or television, streaming and/or posting videos, downloading and/or listening to music, downloading and/or sharing files, involvement in free and/or subscription-based online gaming, reading news, emailing, surfing, and completing school assignments. The findings reveal prevalence rates consistent with the literature on young people's technology use and online activities; moreover, exposure to SEM and cyberbullying were found to have statistically significant relationships with these activities. These are findings consistent with studies concluding that exposure to SEM and online bullying are two of the most serious issues related to young people today and, therefore, warrant continued attention to identifying strategies that can be used to curb risky online behavior. With more and more students using the Internet to access educational content and complete schoolwork in online and blended courses, it is imperative that young people are taught how to safeguard themselves when online.