That's a nice fantasy. They're supposed to enforce broken laws. It isn't unusual for them to abuse their power with mental gymnastics to violate the civil rights of law abiding citizens.

I've had two illegal stops in the past year because in one I took a swig from a soda bottle going by a speed trap and the cop wanted to see if it was alcohol. The other, a cop in an unmarked car tried to run me out of my lane to follow a speeder.

Some years ago I had to deal with a small town gumshoe in Indiana who had staked out an intersection of IN route 55. This was late at night in pitch black darkness. Indiana highway signs look like speed limit signs from a distance and IN55 in particular is hard to distinguish from the 55MPH speed limit signs. The local cops know this and abuse their power to make illegal stops.

https://www.google.com/maps/@40.2361263,-87.2433936,3a,75y,1...

Indiana requires signals 200 ft from an intersection in rural areas rather than the normal 100 ft. The county couldn't be bothered to have an advance sign for the intersection so I didn't know when to signal for the turn. He and I were the only two people on the road but clearly I was a major threat to public safety.