Have I overprotected them?

I have often prided myself on the fact that my kids see the cup as half full. I never really thought they had to be aware of all the bad things in the world, because I was here to protect them right? But what about when they're teenagers? What about when they are venturing out into the real world, on their cell phones, on the internet, with friends, etc...I wonder if I've told them enough about the scary things, about boys and girls that do not have their best interests' at heart, about child predators and abductors, STD's, people that want to take advantage of them, etc. etc. etc., and a myriad of other things that are out there. I had a little scare this week with my daughter and our internet rules and I had to cross the line of showing her the scary...the pictures of the sex offenders that live near our house, the ages of their victims, pictures of kids that have been abducted. How does a parent get across that I don't just make these rules to be mean, I make them to perhaps save my child's life? AND how does a parent do that without invoking so much anxiety for the child that the child can no longer live the carefree child life she used to live? Those are the questions I ponder this evening as the parent of not one, not two, but three overprotected teens.