Unprecedented interest in income inequality has sent a complex book by economist Thomas Piketty to the top of the charts on Amazon.com.

"Capital in the Twenty-First Century" presents centuries of data on the accumulation and distribution of capital and chilling insights about the present and the future. Income inequality has been getting much worse for decades, and this could just be the start.

If Piketty is right, then global politics could get antagonistic, unstable, and potentially dangerous.

Rising inequality could also hurt the economy, as Wall Street is starting to notice. As noted by Société Générale strategist Albert Edwards, "you don't have to be a communist to conclude that high levels of inequality not only adversely affects long-term growth, but also increases the economy’s vulnerability to recession."

We've gathered charts from Piketty and others that show the scale of the problem.