Everybody should speak according to personal experiences.
Mine have been mixed. I've seen police brutality first hand. I've been treated mostly with respect.
Only rookies get cocky I guess. Either they mellow down, or are kicked out sooner or later.

My case is more complicated. I have issues with all authorities. Judicial, penal, scholar, clerical and marital.
The armed forces, the police, the firemen, the politicians, the teachers, the parents, the priests, the judges, the inspectors, the press, even security guards represent authority.
I hate authority and all of those that represent it. Did I mention I hate authority?.
I also hate most of the people that admire those on authority posts. And call them heros for saving a cat. Authoritiy lover in general.