Just look at "Cops", the TV program. What do they do, fight the mafia? No, harassing the small guy trying to buy some speed or a hooker. Pathetic.
and they often pull people over for no good reason just to run a check for warrants.
i used to frive a chevy astrovan, a car typically driven by mexicans, and when i would get off work at 3am i would get pulled over at least every other week. their excuse was that i was weaving in my lane. that is subjective and i believe an all encompassing excuse to check the driver.
i had gotten pulled over by the same cop twice and i said to him, "can't you see that i am white? why are you harrassing me?" he said, "i am sorry sir, sorry to trouble you."