The creator of the chart, documentary filmmaker Matt Groff, Tweeted the following in response to a question about where the $1.5 trillion figure comes from: "Short answer: chart shows only fed drug control, $1.5T refers to all costs assoc. w/ drug prohibition, blog on it shortly."

First off, I take the blame for not seeing the discrepancy. Shame on me.

But here's the funny thing: While the $1.5 trillion figure doesn't correspond to the numbers at right, it's actually low. In 2010, the AP put the 40-year tab of federal drug control spending at $1 trillion.