Do you remember what happened at the ‘68 Olympics in Mexico City? A bunch of American radicals stimulated a bunch of Mexican radicals to riot. The Federales acted.
http://en.wikipedia.org/wiki/Tlatelolco_massacre
So I am under no illusions about liberty in Mexico. Even tourists headed to Rocky Point had better take the right exit, or they may very well end up surrounded by soldiers with M-16s pointed at them.
And that was before the cartels started butchering people.
I am very serious when I say Mexico is not a nice place right now.
I think their ability to act would quickly disappear once a certain threshold of sheer numbers is met.