Exactly. Highest per capita incarceration rate in the world, save Seychelles. Slavery 2.0 meets prison-industrial complex and voter disenfranchisement. The US justice system is the opposite of reform-based systems like those in many Scandinavian countries. It's mean, expensive and reinforces a type of social apartheid.

The Census counts prisoners according to the "usual residence rule," assigning them to their prison for purpose of location and, of course, redistricting. A prison is a good way to get a lot of bodies to populate a district and ensure they won't vote.