"In the British model of policing, police officers are citizens in uniform. They exercise their powers to police their fellow citizens with the implicit consent of their fellow citizens. Policing by consent is the phrase used to describe this. It denotes that the legitimacy of policing in the eyes of the public is based upon a general consensus of support that follows from transparency about their powers, demonstrating integrity in exercising those powers and their accountability for doing so."
http://en.wikipedia.org/wiki/Peelian_Principles
"In the British model of policing, police officers are citizens in uniform. They exercise their powers to police their fellow citizens with the implicit consent of their fellow citizens. Policing by consent is the phrase used to describe this. It denotes that the legitimacy of policing in the eyes of the public is based upon a general consensus of support that follows from transparency about their powers, demonstrating integrity in exercising those powers and their accountability for doing so."