Interesting article that discusses the walls being built to separate people around the world. The Brazilian example is especially relevant and has some great quotes that give a personal insight into the disparities within the country.

"Ghana's population explosion As the world population hits 7 billion, John Vidal returns to the country of his birth to find the midwife who delivered him and to see how Ghana is dealing with a leap from 4 million to more than 25 million people"