He actually went to Soldier of fortune magazine and asked them what people on the Earth are being shat upon the hardest.
Their answer: The Karen
The opening shots of the film show actual villagers killed by the government, it is not fx, those are actual people.
Those bastards have been known to burn children alive and force the family to eat them.
They torture and murder parents in front of the kids, they impale babies on poles while the family screams.
Really horrible stuff.
So Rambo goes apeshit and kills dozens with the fifty, he promises the goriest fight ever put on film and I for one can't wait.
Too bad it issn't real.