In the Neolithic era (Nation level), I killed all the green AI's hunting parties. I pillaged his last outpost, made an outpost on the same tile, and built a city on it. From that point on, my city served as a spawn point for his 4-unit hunting party bands, even though he had nothing else on the map. At some point later on, somehow, the AI got enough stars to become a civ. How? Who knows. The only units he had up until then were the hunting parties he spawned in my city, which I was killing every turn. Anyway, at that point, instead of hunting parties spawning in my city, he spawned 4-unit scouts bands. Through the entire game, I've kept units in that city to kill his stupid units. My units get three promotions for the kills, move out to the world, and I replace them with others. Now, I'm in the Industrial era, and this stupid broken AI with no city is still spawning four scouts per turn in my city. 

This would be funny if it wasn't so tedious having to kill these things, all four, one by one, every single turn. If this isn't a bug, it's a serious design flaw. Just look at this stupid thing. It is literally impossible to take this game seriously when two months before launch this is going on. I get that the Dev has some "everyone gets a trophy" thing going on...but this is ridiculous.

Here is my interface with this AI that has no cities. This thing is probably getting agrarian stars, even though the only way he gains population is the four units he spawns in my city, and I kill them all every turn. This is broken.

I declared war on this thing, and it lost all its war support the very next turn and gave me $4000 in war reparations. Needless to say, I'm going to declare war on it again. Lol. :|