That compares with HIV prevalence among black men in that age group who aren't incarcerated of 3.3%, according to tests by the Centers for Disease Control and Prevention.

WSJ: Why Surveys Should Listen More to Prisoners

Mr. NICOLAS SARKOZY (Minister of the Interior, France): (Through translator) In the face of more frequent and more violent crime in Saint-Denis, I don't understand why the number of people incarcerated is down.

NPR: Violence Overshadows Upcoming French Elections

Disney and his team of animators figured this out long ago (I still can't watch the scene where Dumbo visits his incarcerated mother).

CNN: I don't love your dog -- and you can't make me!

For that reason -- and since communications between inmates and nonprisoners are monitored by prison officials -- current inmates can't discuss mackerel transactions without risking discipline, say several lawyers and consultants who represent incarcerated clients.

WSJ: Mackerel Economics in Prison Leads to Appreciation for Oily Fillets