The problem is not simply the “filter bubble,” Eli Pariser’s notion that personalization-driven algorithmic systems help silo people into segregated content streams. Facebook’s claim that content personalization plays a small role in shaping what people see compared to their own choices is accurate. And they have every right to be annoyed. I couldn’t imagine TimeWarner being blamed for who watches Duck Dynasty vs. Modern Family. And yet, what Facebook does do is mirror and magnify a trend that’s been unfolding in the United States for the last twenty years, a trend of self-segregation that is enabled by technology in all sorts of complicated ways.