I dont watch the show but do watch a lot of movies.
I think you can relax. Its not about the alien horde. I believe directors and writers are just trying to add a layer of authenticity to shows and movies. In many of the newer movies and shows if a character is from Russia, Serbia, Africa or what have you I have seen a trend where those characters speak in what is supposed to be their native tongue and it is subtitled.
I actually prefer it. I watched a couple of episodes of an old TV show last night as we were heading to sleep where the characters were supposed to be from somewhere else .. they just spoke English in these absolutely terrible made up accents that were NOTHING like the accents of the people they were trying to represent. They were going for English with a French accent and it just came off Italian, Greek, Spanish goobledy gook.The accents were so bad I had trouble following along and would have preferred their bits had been subtitled and after a while I just turned on Closed Caption.
If you are looking for the enemy .. you don't have to look under the bed ... the enemy is hiding in plain sight. Its not those evil Guatemalans who decreed that men should be allowed in the girls bathroom, It wasn't the terrible third world Argentinians who decided we cant say the pledge of Allegiance before school starts, It wasn't those Hondurans that said a highschool football team cant pray before a game. I didnt see a lot of Brazilians in the room where Americans are trying to stage a coup of a duly elected President and its not those pesky Chileans trying to take your right to own a gun away.
No .. the people doing that, the ones that are systematically brick by brick tearing down America .. well .. without a picture I cant say for sure .. but I bet they look a lot like you.