Thats a brilliant question. I might be in the minority here, but one thing I've always wrestled with is whether ACAB is best understood as a critique of an institution or as a judgment of every individual within that group.

Personally for me, the strongest argument has always been the institutional one. I have deep criticisms or even hatred of how police power is (ab)used, of the historical role in protecting existing power structures, and of the ways in which accountability regularly fails.

At the same time, I'm less convinced that every individual who wears a badge is equally malicious or equally committed to those structures. Some actively reinforce them, some passively uphold them, and some try, with varying degrees of success, to mitigate harm from within. My best friends father is serving as a police officer here in Germany, and he is as left as it gets. He became a cop bc "that's where the change needs to happen". He's openly anti-racist, supports refugees, is active in labor and union issues, has privately attended demonstrations against far-right groups, and has never been shy about criticizing police misconduct, especially if it's about his very own colleagues.

That's why the Edward Snowden question is interesting. If someone works within a coercive state institution, but then exposes wrongdoing at enormous personal cost, what does that tell us about the institution? What about the individual?

So I'd say: the police is one of the biggest problems of our societies. Comes right after the fight against climate change and the fight against capitalism. But IMO it's wrong to say ACAB, because the problem is too complex for such a simple solution. Philosophy says it's every individuals own action that should decide over their fate. Feel free to argue with me, since I'm open to changing my mind.

Edit: typo