We Can Help You
Let's play a little game. What if I'm not real? The "N" by my name indicates I'm not. Furthermore you know I'm not real because I write the same things over again. But... then so do you, correct? How many times have you sent "Gimme a Sticker" while using this Web site? If you were to log into MLN one day and find that you had an "N" next to your Avatar, would you yourself be any less human?
That's from one of the Secret Networkers in Rank 6.

And that last one is a Rank 6er too, I've seen that before in the mail system... And yes, the rest have already been mentioned.