The study found that behavioral and psychosocial problems were more prevalent and severe in relation to the frequency and intensity of online harassing behavior. Rule-breaking behaviors were reported seven times more often by frequent perpetrators of online harassment compared to otherwise similar youth who never perpetrated online harassment in the previous year. Aggression problems were nine times more frequent among youth who harassed people on the Internet compared to otherwise similar youth who did not perpetrate online harassment. Girls were 50 percent more likely than boys to be infrequent perpetrators of Internet harassment, and boys were three times more likely than girls to be frequent perpetrators of online harassment. Six percent of all the youth reported conducting frequent Internet harassment of other users, and an additional 6 percent reported occasional use of online harassment; 17 percent reported limited perpetration of Internet harassment in the previous year. These findings reinforce previous research, which found that youth who harassed others online were likely to have significant behavioral and psychosocial problems. This suggests that frequent Internet harassment of other users may indicate co-occurring psychosocial problems. Study data were obtained from the Second Youth Internet Safety Survey, a national telephone survey of youth between the ages of 10 and 17. Interviews were conducted between March and June 2005. Youth were asked about two types of online harassing behavior: the number of times in the last year they had used the Internet to harass or embarrass someone they knew and disliked and the number of times they had made rude or nasty comments to another user online. 1 table and 33 references