How the internet keeps poor people in poor neighborhoods, Alvin Chang, Vox, December 12, 2016, available here

Housing discrimination happens all the time. But the shocking thing here was just how visibly the tool let advertisers discriminate. On Facebook, all they had to do was check a box.

It was reminiscent the overt systems that forced housing segregation in America, now and in the past. In the 1940s, the federal housing administration refused to back home loans for black people — and those who wanted to live near black people.