Facebook was again hauled before Congress this week, this time to answer for a set of stories published in the Wall Steet Journal saying the company has internal research showing its tools hurt kids -- Instagram exacerbates body image issues for teen girls, for example -- but it hasn't really done much about that.  So, what now? What next? Here to help untangle that is David Hoffman, professor at Duke University Sanford School of Public Policy -- he's a  cybersecurity expert.