I am not one to search myspace for teens, but from what I hear, you best check to see what photos your daughters are posting of themselves. I know that many of the adults (over 18) post some pretty sexy photos, even the shy people. Remembering back a few years, I recall how it was "cool" to be liked by everyone, and for some people today, posting seductive photos of themself on myspace, seems to get the attention. You can see on your home page, the number of people who have checked out your page. I am sure it corresponds directly to the things which are being said and the photos posted by the user.
I find myspace to be a funn connection source for people and music, but I am sure that some people misuse it greatly.