Everyone should see this excellent documentary (filmed in America for Dutch TV), to understand why the so-called "War on Drugs" is a crime against humanity. This is easily the best film I've seen to date on the subject: gripping, powerful, precise, appalling.
The first minute or two is an introduction in Dutch, but the rest is in English, with Dutch subtitles.
In a sense, I guess the War on Drugs is to American domestic policy what the War on Terror is to its foreign policy. And it's been going on for at least 30 years…
If you prefer reading to watching, try Smoke and Mirrors: the War on Drugs and the Politics of Failure by Dan Baum – ten years old, but sadly getting more relevant every day, as shown by recent US incarceration figures.