I'm going to have to say that there is no second person. You can say what you want about controlling the character through the enmies eyes, etc...but you're just stretching the analogy.
In grammar....
1st person...I like to go to the store. It gives me something to do.
2nd person...You walk into a room. You notice something different and then you see it: Your girlfriend is sleeping with another man.
3rd person...He reaches into the nightstand, quietly, and pulls out the gun he's only shot once at a firing range. The grip is warm against his fingers and his hands aren't shaking like they should be.
FPS games are told from the first person perpective. You are the avatar.
Third person shooters have you portraying an avatar on the screen (from whatever angle).
The second person analogy just doesn't apply. Even if you were controlling the character through the enemy's eyes, it would still be a third-person perpective.
At least, that's the way I see it.
