As I stated kidnapping for ransom and extortion or any form of harming innocent civilians even families of police or politicians is very taboo/frown upon in the Mexican underworld. The breaking of this rule is more or less what sparked the war between the cartels(killing of Barbie's brother by the Zetas and Zetas extorting the civilian population ,"derecho de pizo" quotas on civilians etc. and taking on rival's plazas of course). That's why when cartels put narco-banners they say they are going to exterminate the scum or "lacraZ"(with capital Z to refer to Zetas) anyone that extorts or kidnaps for ransom Zetas or not.