MONDAY, Jan. 5 (HealthDay News) — More than half of teens who use the social networking site MySpace have posted information about sexual behavior, substance abuse or violence, new research shows.

The good news, according to a second study from the same research group, is that a simple intervention — in this case, an-e-mail from a physician — made some of the teens change their risky behaviors.

“I was surprised, at least to some extent, at how clearly teens were discussing behaviors that we struggle to get out of them,” said Dr. Megan Moreno, an assistant professor of pediatrics at the University of Wisconsin-Madison.

“Once we started getting the findings, we wondered, why are they doing this?” Moreno said. “Do they not get it? And, if they don’t understand that this is public, can we send them a cautionary message to let them know just how public their information really is?” Moreno was working at the University of Washington and Seattle Children’s Research Institute at the time the studies were done.

I know that I”ve posted this before, but in rereading it, it seems even more relevant now.