I am surprised that you don't see more of this. Although access to firearms is theoretically restricted in Mexico, that obviously doesn't stop the bad guys. And since so many of the police are aligned with the bad guys, it is not clear why people would be particularly concerned about their opinion. I am not trying to criticize, just clarifying my confusion.
Mexican Vigilantes Seize Town, Arrest Police
Borderland Beat, 27 March 2013 (Sourced from: NY Times, Maspormas, Miami Times)
Hundreds of armed vigilantes have taken control of a town on a major highway in the Pacific coast state of Guerrero, arresting local police officers and searching homes after a vigilante leader was killed. Several opened fire on a car of Mexican tourists headed to the beach for Easter week.
Members of the area's self-described "community police" say more than 1,500 members of the force were stopping traffic Wednesday at improvised checkpoints in the town of Tierra Colorado, which sits the highway connecting Mexico City to Acapulco. They arrested 12 police and the former director of public security in the town after a leader of the state's vigilante movement was slain on Monday.
As I understand it, the areas with the largest vigilanti movements, are also the areas where the citizens have a history of confrontation with the central government. Other areas report vigilanti justice, but that seems to be of a smaller ad hoc nature, rather than community based.