R. Yaakov Horowitz offer part two of his essay on child abuse and molestation with "Safe and Secure" (link):
Sad as it may sound, the painful reality is that you cannot provide your children foolproof protection from what are, in my opinion, the greatest physical and spiritual dangers that they might face during their formative years; abuse and molestation. Why? Because it is simply impossible to follow them wherever they go, all the more so as they pass through their pre-teen and teenage years. Furthermore, it is impractical and harmful to their sense of security to raise them to be frightened or suspicious of every adult that they meet. Finally, it is important to understand that although most of the high-profile abuse cases are school based, they are only a tiny percentage of the instances of molestation. Abusers are far more likely to be extended or close family members, older kids in the neighborhood, family friends, neighbors and peers.Continued here
With that in mind, I suggest that you view things from a broader perspective and think of protecting your children from abuse/molestation in the following four domains:
1) Training your children about healthy and appropriate norms for behavior between adults and children;
2) Equipping your children with the knowledge of what abusive behaviors are;
3) Empowering your children with the self-confidence to assert themselves when their personal space is violated; and
4) Supporting your children if and when they report to you that they are feeling that things are out of order...