Facebook released its new Messenger Kids app this week. It allows parents to monitor exactly who their children are communicating with on the app. It's aimed at kids ages 6 to 12.  (Under federal law, kids under 13 aren't allowed to have Facebook accounts.) And it keeps everything inside the Facebook ecosystem — the new app would require parents to be Facebook friends if their kids want to chat. Marketplace Tech host Molly Wood talked with Amanda Lenhart, deputy director of the Better Life Lab at the think tank New America, about how this could affect kids’ online presence — and privacy.