Have you ever noticed how emoticons can change the meaning of a sentence. For example:
Saying: You're a jerk. This makes it sound like that person is a jerk.
Saying: You're a jerk :D. This make it sound your just joking, or it's some super secret code name. Here's another, possibly greater example.
Saying: Shut up! This makes it sound like you want the person to shut up now or else.
Saying: Shut up :). This makes it sound like the person said something mean to you (jokingly) and you were both laughing.
Do you see what I'm saying?