When gangsters dump headless bodies in Mexico or park vehicles filled with corpses, they usually leave behind a cloth banner with a message.

The messages are invariably taken down by law enforcement as soon as officers arrive on the scene. Major media outlets rarely print or post photos of the cloth banners.

Anyone interested in the workings of multitude of criminal gangs and drug mafias, though, is interested in the messages these banners contain. Often written in “hillbilly Spanish,” replete with spelling errors and poor grammar, they nonetheless reveal feuds within gangs, motives for gang-on-gang violence, the changing contours of the geography of terror and who mobsters have in their deadly sights.

To understand public security issues in Mexico, one has to use the banners as a window into what gangsters are thinking. They are one of the few windows out there. Look on either this blog or this one to see a sample of banners. (Warning: those blogs often contain very graphic images of bloodshed.)

Yet politicians occasionally rail against the banners. A tweet by someone at insightcrime.org led me to this Proceso article about how the chief of staff to the governor in Colima state said any media outlet that shows the banners or reports on their contents becomes “spokesmen for organized crime.”

The banners, Rene Rodriguez Alcaraz said, “are designed to instill terror in the populace.”

This is a common refrain. Look here for a Spanish-language article on remarks by Roman Catholic Archbishop Jose Guadalupe Martin Rabago of Leon last month in the same vein. He is quoted saying this: “In any case, what I think those narco-banners want is to create a climate of terror, so do not play into the hands of those who want to intimidate. I think we would do well not to give publicity to the messages in these banners.”

I respectfully disagree. Looking past the violence associated with the banners, which is invariably horrific, they still give insight into the minds of the enemies of law and order. If nothing else, one can take solace that those working for the kingpins are usually a visceral group, criminally astute perhaps but poorly educated and often not very intelligent. That is not the message gangsters want to convey in the narco-banners but it might be a useful rendering of who they are.