The danger of cartel violence is an everyday reality in much of Mexico. It's been that way for years.

So when they start giving out with warnings like these, you know it must be getting really bad.

A former FBI assistant director is warning Americans that nowhere in Mexico is safe from the cartels, after the kidnapping of four US citizens and murder of two last week.

Those four U.S. citizens were reportedly taken by the Gulf Cartel after being mistaken for members of a rival gang. That's how deadly these guys are: Even in their blundering stupidity they can still kill you.

These warnings thus take on added urgency:

Former FBI Assistant Director Tom Fuentes told NewsNation that even what look like 'safe' resorts may not be as secure as many Americans think.

'While you're on the highway, you're vulnerable. Now, in this case, it sounds like the cartels had set up a checkpoint, basically like a tollgate, that you had to go through them.

'And it sounds like the van tried to run past that. And that's when the cartels opened fire,' he said.

Former national security advisor Nayyera Haq, meanwhile, argued that "the majority of Mexico is actually in the control of cartels," while retired FBI Special Agent Richard Kolko "warned US tourists against driving into Mexico, and advised dressing inconspicuously once they are there:"

'Do not drive across the border if you want to go to Mexico. Certainly go to Mexico, but be careful. Fly in. Go to the tourist areas. That's where you're going to be the safest. Carry that cell phone.'

All very helpful advice but I gotta say at this point in time if it's a choice between going to Mexico or staying in the United States...