Nothing. Once I called this girl when I was with my friends, and she answered by screaming down the phone, so I hung up and called again. This is how it went:
Girl: Who is this, I'm really scared
Me: Woah, wtf. Do you do this when you're mom calls you as well?
Girl: No seriously, who is it?
Me: You can guess, can't you?
Girl: Ermmm...
Me: I'll give you a clue... [censored for racism]
Girl: Is it Will? (My best bro who's French... not black...)
Me: ... Are you serious.
Girl: He always calls himself my [censored] in paris.
Me: Okay... I'm actually black. Big clue?
Girl: Roman? (Some Asian guy who's a friend of mine. Definitely not black)
Me: ARE YOU JOKING ME?!!?!!
Girl: What??
Me: Okay.... *breath* a bigger clue... Name begins with "A" and ends with "Lex"...
Girl: Is this Louis?!
Me: .... *facepalm*
*hang up*
Yup, some of my friends are this simple! =D