Cyberbullying is more common than you think, and teens aren't telling their parents about it, says a study in the September issue of the Journal of School Health. In fact, some 72 percent of teens who are frequent Internet users say they've been the victim of online bullying at least once during the past year, with 90 percent of them saying they don't tell their parents about the online incidents, mainly because they feel the need to deal with the problem on their own and are fearful of parental restrictions on Internet use, the study adds. "Extending the School Grounds?—Bullying Experiences in Cyberspace" goes on to say that online bullying is associated with in-school bullying, with 85 percent of respondents who reported at least one online incident also reporting being harassed in school. The most frequent online and in-school bullying involves name-calling or insults, and the online incidents most typically take place through instant messaging. Repeated school-based attacks increase the likelihood of repeated cyberbullying more than the use of any particular electronic communication tool, the study says.