'Narco-banners' reportedly threaten Americans in vacation hot spot where cartels rule like mafia: expert

Two alleged "narco-banners" that surfaced online this month, which warned Americans to stay out of Mexico's Los Cabos region, have sparked concern about cartel intimidation tactics, even as local officials insist the signs never existed.

"When you're dealing with a cartel that's that serious and sophisticated and right at our back door, we have to take it seriously," Peters said. "It's a shot over the bow to both governments. They rule by threat and intimidation - the same way the mafia did."

In the 1980s and '90s, Colombia's cocaine cartels controlled entire regions through intimidation, corruption and fear tactics that are nearly identical to what's now unfolding in parts of Mexico.

"Their strategy is simple: if they can control the levers of power in a nation through intimidation, then they control the nation," Peters said. "They assassinate police, judges and journalists, and they use fear to rule, the same way authoritarian regimes do."

That closeness, Peters said, makes Americans prime targets for extortion, kidnapping and terror.

"My advice is simple: don't go unless you really need to," he said. "Be cautious, and stick to places with an established record of safety."