Here's a warning to parents and teens about the potential spread of sexting photos: Police in Emmaus, Pennsylvania are investigating how nude photos of high school students wound up on an unnamed pornographic Web site.

According to reports, the photos were taken by the teens themselves and shared with classmates. It's not clear right now how the photos wound up on the adult Web site, or how they were discovered. Police believe, however, that the photos were on the site "for some time."