Many leftist individuals and groups like to use the acronym ACAB as a slogan. It stands for “All Cops Are Bastards” and, obviously, expresses disdain for the police. Similarly, purported pacifists and anti-militarists use the slogan “Soldiers Are Murderers” (which appears to be more common in German-speaking countries).
Both slogans are strong, generalized statements. As such, they label an entire group of people and, by their internal logic, do not allow for any exceptions. This is the basic reason why these and similar slogans are not just factually wrong, but actually advance goals counter to those of the people most commonly using the slogans.
The police and the military (as organizations) are agents of the state and they execute the policies undertaken by the state. Thus, each individual police officer and soldier executing the policies of the police or military are state agents. However, they are also humans. According to an employment consulting agency, the median salary of a police officer in the United States is USD 50 348. This is noticeably higher than the median income of all full-time workers in the United States, which is USD 39 336. However, this absolute difference still places them not far above the income median (extrapolating from a chart regarding household income inequality). In short, police officers are not particularly financially privileged and they suffer from issues similar to other employed persons (fear of unemployment, rising expenses, etc.) and should thus, as individuals, not be regarded to belong to the oppressive elite which controls the state.
Why, then, are they still addressed as the enemy by many in the form of ACAB? The slogan serves to humanize and individualize a conflict which should be waged against an oppressive system. Individualizing the abstract, unclear “system” and distilling it down to any given human agent of the state is exactly what shields such a system from direct attack. Instead of attacking the oppressive system, people who subscribe to ACAB psychologically or physically attack their fellow people and thus follow the misdirection and obfuscation of the system. Divide et impera works.
ACAB and similar slogans are therefore nothing but instruments of oppression. They are fundamentally counterrevolutionary.
I will disregard the easier argument against such slogans as to their factual truth. Suffice to say that one police office who is not a bastard and one soldier who has never killed anyone render them wrong.