How a viral fundraiser earned a cool $220 million for ALS

This year, a challenge to Facebook users to douse themselves in ice water became an internet craze, raising millions for ALS, or Lou Gehrig’s disease. Gwen Ifill talks to Nancy Frates, the mother of the man who inspired the ALS Ice Bucket Challenge, about the impetus for the viral fundraising campaign and how it has advanced awareness and research of the disease.