Lets take a family. If one brother had the tattoo then his father, brothers, and all male children were arrested regardless of the age, health, or any other evidence. Not to mention there was never any trials, charges, etc. for a huge number of them. 

Cje95

Bell_curve

bitcoin

Argentina aims to learn from El Salvador's Bitcoin success

> mass incarcerating males

I mean, every indication is that a high % of the entire El Salvadorian population really were criminals. They literally tattooed it on their faces. I don't see how you can complain about mass incarceration if a "mass" of people really are criminals.