A ticket for what you think

A police stopped a man on the street.

Police :Hey! You were speeding.
Man   : No, I wasn't.
Police : Yes, you were. I'm giving you a ticket.
Man   : Hey! I was driving just fine.
Police : You can tell that to the judge.
Man   : Would you give me another ticket if I called
             you a jerk.
Police : Yes, you would.
Man   : What if I thought that you were a jerk?
Police : I cannot give you a ticket for what you think.
Man   : I think that you are a jerk.