A cop stops a man for running a stop sign and the subject gives the cop a lot of grief explaining that he did stop. 

After several minutes, the cop explained to the gentleman that he didn't stop, he just slowed down a little. 

The gentleman said 'Stop or slow down, what's the difference?'. 

The cop pulled the guy out of the car and hit him with a nightstick for about a minute and then said, 'Would you like for me to stop or just slow down?'