Information security and privacy on the internet are critical issues in our society. In this research, we examine factors that influence Internet users' private-information-sharing behavior. Based on a survey of 285 preteens and early teens, who are among the most vulnerable groups on the Web, this study provides a research framework that explains an internet user's information privacy protection behavior. According to our study results, internet users' information privacy behaviors are affected by two significant factors: (1) users' perceived importance of information privacy and (2) information privacy self-efficacy. The study also found that users believe in the value of online information privacy and that information privacy protection behavior varies by gender. Our findings indicate that educational opportunities regarding internet privacy and computer security as well as concerns from other reference groups (e.g., peer, teacher, and parents) play an important role in positively affecting the Internet users' protective behavior regarding online privacy.