it's facebook's fault? >> i think it would be too easy to suggest with a tweet to an algorithm somehow the polarizing u.s. politics would evaporate. i think it dissolves people of asking themselves harder questions about historical, cultural, social and economic reasons that led to the politics with he have in the u.s. today. look, i think researchers say the same thing. if you look at research published i think just a few weeks ago by some stanford researchers, they looked at 12 countries, including the u.s., across europe and north america and australia and new zealand to trace the rise of polarization over the last 40 years and they found in many -- half the countries, about six of the 12, polarizations actually declined even as social media use has gone up. the u.s. is quite unique among those 12 countries seeing a much higher increase in polarization over the past four decades. i think simply saying it's got to be because of some social media apps people use i think is woefully simplistic.