How U.S. is countering Islamic extremist propaganda machine

President Obama reiterated his promise to destroy the virulent Islamic State Tuesday while talking about the Orlando mass shooting — and how gunman Omar Mateen, a U.S. citizen, may have been radicalized by online extremist propaganda. NewsHour producer P.J. Tobia reports on U.S. efforts to win the hearts and minds that the terrorists are trying to co-opt on the Internet.