This article I found has to do with a group of vigilantes that have taken it upon themselves to fight back against a specific drug cartel. They were initially well-received, since that particular cartel was causing a lot of trouble in the area, but apparently the vigilantes were starting to cause problems of their own. In addition, the Mexican government believes that they have a better handle on the situation than they used to, and that the vigilantes are no longer needed.
This just goes to show what a complicated issue Mexico's drug cartels are. They cause a lot of problems, but the way people react to those problems can be an issue in of itself.
