  Pariser notes that while democracy “requires citizens to see things from one another’s point of view,” we are instead increasingly “more enclosed in our own bubbles.” He goes on to note that democracy also “requires a reliance on shared facts,” but instead we are being presented with “parallel but separate universes.” To illustrate how this trend away from citizens having shared facts can be so dangerous for a democracy, Pariser uses the example of the debate about climate change in the U.S during the past decade. He points out that studies have shown that between 2001 and 2010 many people’s beliefs about whether the climate was warming shifted significantly, based on one’s affiliation with a major political party. Pariser notes that a Web search for “climate change” will yield very different results for a person whom the search algorithm determines to be a Democrat than for someone it determines to be a Republican. He also notes that the search algorithm will generate different results for someone it determines to be an oil company executive vs. an environmental activist.