Before anyone says, "Why harass these people? They're just trying to make a living." Think about it for a little while.
Have you bothered to "think about" this? Police officers have a sworn duty to uphold the law. They don't write it. If you have a problem with the law your issue is with the Legislators not the cops. (This is the very definition of "killing the messenger")
Police officers do have a sworn duty. But some of them do not uphold their oaths. Some of them even break the law outright. It's therefore quite possible to have an issue with law enforcement, separate from the laws themselves.