I can understand that a lot of times it's because of a reason we simply don't know being in our cars. As mentioned before about getting called out but then another unit being closer. But me personally I've seen it way too many times where I know its just an abuse of power, like the cop that lives in my neighborhood literally down the street from my friend, who one night decided to pull a nice 180 km/h run down mcknight. We recognized the #'s on the truck and knew it was the guy down the street from my buddy. So when we got to his street we see the truck parked there and the cop having a beer in his driveway and chatting with the neighbor. F'ing emergency indeed.... And this wasn't the first time.
"Excuse me, is your refrigerator running? Because if it is, it probably runs like you... very homosexually."