I'd like to add that I've figured out WHY Nintendo doesn't want us to give our friend codes away to everyone...
It won't really matter for now, since you can only play Mario Kart and all you can do is race but when Animal Crossing is out...
Only "friends" can visit your city in AC, and if you gave to everybody and their cat, then you just might get some unwanted visitors who CAN "trash" your town, you can ban them, but it will be to late...
