I think it's sad that it's come to this. That we have to use tracking devices in kids to keep them around. For little children, imo, the parents should stay with them at all times. For older children, they should be allowed a bit of independence, but, as bassman21 mentioned, "parents need to teach their kids how to prevent something happening in the first place and what to do if it does." Most children should know the basics, like not talking to strangers and not walking off with strangers. I know this was taught through schools, children's programming, and by my parents when I was a child, so I'm certain they'd still teach it now.