When the .gov won't help you, it gets bad enough,

You do what you have to.
An audacious band of citizen militias battling a brutal drug cartel in the hills of central Mexico is becoming increasingly well-armed and coordinated in an attempt to end years of violence, extortion and humiliation.

What began as a few scattered self-defense groups has spread in recent months to dozens of towns across Michoacan, a volatile state gripped by the cultlike Knights Templar, a drug gang known for taxing locals on everything from cows to tortillas and executing those who do not comply.

They don't trust LE, they don't trust the army, and they have reason not to.  So,
The groups ring a church bell or shoot off fireworks, and thousands pour into the streets, he said.

“It’s curious,” the doctor said. “These people who had tied people up, blindfolded them and executed them, when we shoot, they run. I think they are afraid of us.”
He and others also wonder how they have been able to do what far-better-armed federal security forces have not.

“Just look at the military people — they have gear, they are trained, very capable,” said Pimentel, the butcher. “But here, the locals, the farmers, the workers, we are doing the job. Now we have to be sure those people are not coming back.”
You'll note that it mentions the carrying arms in a country were just about anything is illegal for the commoners; but the army seems to be giving a blind eye.  Knowing who the real enemy is, I'd guess.