Criminalizing People as a Political Act

I was listening to NPR today and happened to catch a segment on Talk of the Nation on "The Untold History of Post-Civil War 'Neoslavery'". In this segment, the author of the book called "Slavery by Another Name" talked about how after the emancipation proclamation went into effect, lots of black men were arrested for all sorts of crimes including vagrancy and various made-up crimes so that they could be made to work for free- thus a slavery by another name. First, i was disappointed that no one, no callers, nor the interviewee mentioned that this is still going on today in the prison industrial complex. How many black men are imprisoned right now?

Black males ages 25-29: 11,695 per 100,000. (That's 11.7% of Black men in their late 20s.) (Source).

Anyway, this discussion of laws created to basically continue to enslave mostly black men "after slavery" made me think of a point that i have made before about people being criminalized out of a political/economic motivation- specifically undocumented immigrants being made "illegal" to justify certain treatment. This way, they are kept from being able to fight, to some extent, for basic human rights, and people are made to actually believe that they don't deserve certain rights because they are "illegal". Of course, they are only "illegal" because it is in the interest of the government and businesses to make them so, so that we can have a permanent underclass to exploit the labor of. Anyway, you get the point.