I never said they don't kill innocent civilians which rarely happen (if they do it's big news/big deal) I said they don't behead or butcher innocent people. What I did say is that kidnapping for ransom and extortion (which the Zetas are know for) is frowned upon the Mexican underworld, I'm not saying they don't do it.
Yes, the Zetas as well as La Familia are known for extortion. But no use splitting hairs. They're all part of the Mexican underworld. I will agree that they leave the butchering to their rivals. Obviously for intimidation purposes. Usually little reason to do that to civilians. But that's not out of any kind of moral code on the part of the cartels. For instance, the recent killing by the Sinalo cartel of 28 rival cartel members in Acapulco, including 16 of them beheaded, wasn't because they really cared about the local businesses being extorted. It's simply a tactical ploy to gain loyalty by the people by acting like their protectors.
