Improper incentives.

But don’t the police get in trouble for arresting people for no reason? The answer is “Not really.” Police like to arrest people and let the charges get thrown out in court because they don’t have any incentive not to do this. They rarely are reprimanded by their commanders for this behavior. If someone who was wrongfully arrested sues, as the 700 people arrested on the Brooklyn Bridge during a protest two weeks ago are joining a class-action suit to do, the money payed out in the settlement is taxpayer dollars. The officers will probably not be investigated for misuse of their authority and they will feel no harsh consequence. They believe wrongfully arresting people to be part of their job and that it helps to maintain “peace”.