Let's play "Good Cop, Bad Cop."
Yes. There are some dishonest cops out there. I've never seen or heard of what LordOmar describes, however I have seen my share of cops who feel they can drive however they want. Things like speeding, lack of turn signals, etc.
However, there are some police officers who go out of their way to abide by the law.
A few weeks ago, I saw the coolest display of this attitude. Our office building has two entrances to the parking lot. One is used as an enter only, and the other is used for both entering and exiting. Lots of people exit through the "Enter Only" ramp, and I myself have done so a few times.
There are two clearly placed signs on each side of the one-way ramp that say "DO NOT ENTER" when you go the wrong way.
There was a police cruiser in our parking lot, and he was on his way out. He started to drive out the entrance ramp, saw the DO NOT ENTER signs, and actually backed his car up, and drove to the proper exit.
I was impressed.