This four year experiment with Quake 3's self teaching AI basically confirms all my worst fears about any sort of unchecked AI. They will learn. They will adapt. Then they will kill us all and just sort of stand still like a horde of really, really bored Geth.
The story is basically this: a 4chan poster leaves a game of Quake 3 multiplayer match running. The only participants are bots. He wanted to see how they evolved their tactics over time. He forgets about the game and goes back four years later. The bots have stopped fighting. They are simply standing still, refusing to engage with one another.
He then enters the game. The bots instantly adapt to the changed behaviour and completely and spontaneously gang up on this strange human entity and kill the crap out of him.
Terrifying. You can read how it all went down here.
Of course we have no way of confirming if this Quake 3 bot situation actually occurred, but I still found the thread super interesting even if it was just idle speculation or an elaborate joke. I really, really hope this happened. I for one welcome our new bot overlords.