With almost all social-media-using teens on Facebook, it's only natural that behavior on the network mimics the trials of real adolescence. Rumors are started, cliques form, bullies emerge, feelings get hurt. But digital drama doesn’t always stay online, according a new study of teens' social networking habits.

Twenty-five percent of teens on social media sites have had an experience that resulted in a face-to-face argument or confrontation with someone, according to a study by the Pew Internet and American Life Project, the Family Online Safety Institute and Cable in the Classroom.

Surveying 799 social media users ages 12-17, the study found that 88 percent of them "have seen someone be mean or cruel to another person on a social network site."

That cruelty manifested itself in several ways, including bullying via text message, email, instant messaging or phone, and it often had ramifications beyond the computer, including physical fights.

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Twenty-two percent of the survey said an online experience caused the end of a friendship; 13 percent said they "felt nervous about going to school" the day following an online confrontation; and 8 percent got into a physical fight with someone "because of something that happened on a social network site." The survey was conducted from April 19 to July 14.

The study, titled "Teens, Kindness and Cruelty on Social Network Sites," highlighted an important factor that allows cyberbullies to thrive.

"A majority of teens say their own reaction has been to ignore mean behavior when they see it on social media," the study's authors wrote. Ninety percent of teens on social networking sites said they have ignored instances of online cruelty. Twenty-one percent admitted to joining in to harass others.

Parents can play a crucial role not only by modeling positive online behavior for their teens, but also by checking in on their children's online lives, talking to them about their experiences online and encouraging them to stay safe and be better "digital citizens," the authors wrote.

About half of the parents of social media users (54 percent) said they deploy parental controls to manage their child's online experience (including blocking and filtering the child's access). Even more (77 percent) said they check the websites their kids visit, and two-thirds have checked to see what information about their child was available online.

Still, a watchdog parent does not mean a teen can't find trouble online. "We find that even when parents friend their children on social network sites, it does not necessarily head off problems on those sites," the study said.