no webcams PERIOD! They are only used to see outward apperence.
Put computer in a room where you, the parent, can walk by at any time. This will keep kids from being places they shouldn't be. which brings me to..
No Chatrooms PERIOD! Your kids had friends before internet. (If your kids are laking in the friend department, try to find organizations in your community with potential of meeting new friends) You still have a telephone, tell your kids to call thier friends.
Ask your kids-friends-parents to monitor the internet in THIER homes as well. If they dont see the "problem" ask them not to let your child use the internet at their house.
Remember your children can go to the library to use the internet. They really DONT need it at home.
Parents need to use thier natural radar systems. If something seems wrong, it probably is. I hope my advice seems helpful, and doesn't sound too much like I took it straight from an episode of Dr. Phil (which some of it probably did)..:)