Don't let texting become harrassment!

This year, three teenage girls, students at Greensburg Salem High School in Greensburg, Pa., were charged with disseminating child pornography.

They had sent nude pictures of themselves by cellphone to their teenage boyfriends, who were charged with possessing child pornography.

The legal consequences in this case may have been unique, but the behavior is not. About 20 percent of teenagers have posted or sent nude cellphone pictures of themselves, according to the National Campaign to Prevent Teen and Unplanned Pregnancy, a nonprofit group.

Sending nude pictures, whether it is done under pressure or not, is part of a pattern of teenage behavior that the Family Violence Prevention Fund, a nonprofit domestic violence awareness group based in San Francisco, has labeled digital dating violence. The digital violence can include sending nonstop text messages or posting cruel comments on a boyfriend’s or girlfriend’s Facebook or MySpace page. The behaviors can be a warning sign that a teenager may become a perpetrator or a victim of domestic violence, according to the group.

Almost one in 10 high school students has been physically hurt on purpose by a boyfriend or girlfriend, according to Centers for Disease Control and Prevention research. And one-quarter of teenagers in relationships say they have been called names or harassed by their partner through cellphones and text messages, according to a study commissioned by the clothing company Liz Claiborne, which sponsors antiviolence programs.

About 39 percent of teenagers have sent sexual e-mail messages or instant messages, according to a 2008 study from the National Campaign to Prevent Teen and Unplanned Pregnancy and CosmoGirl.com.

A recent campaign was created to address this problem. The campaign and its Web site, ThatsNotCool.com, encourage teenagers to set their own boundaries. It is intended to appeal to all teenagers, not just those with serious problems.

On the site, teenagers can send one of 35 “callout cards” — brightly colored messages they can send by e-mail, post to their Facebook or MySpace accounts or download — that are meant to tell someone they have crossed a line.

Another great website is safeandrespectul.org. Check out their PSA above.