All Cops Are Bastards, so many anarchists say, usually abbreviated as ACAB. It's true, police are a form of oppression and authority, but does it follow from that principle that all cops are bastards? I don't think so. Cops, as with most members of vertical collectivist organizations tend to be indoctrinated into the organizations and truly believe they are doing right. In addition, most people have been socialized from a young age to believe that cops are necessary to preserve peace and order, so many cops have good intentions, even if they are corrupted by the state. So, no, not all cops are bastards.
But is this literal reading of the phrase and acronym what is intended? Not really. It is used to describe our feelings about cops as well as the institution of police. What is meant by all cops are bastards is really all cops are our enemy. This, as far as I can tell, is true. All cops are our enemy. They may be indoctrinated into being our enemy or forced to be, but we must fight them nonetheless.