Earlier quoted context omitted.
We try to reason about the world. When the world appears to be unjust and we feel powerless to change, we (humans) tend to fabricate justifications for the actions of others. So that we feel better about themselves and we can move on thinking bad things won't happen to us. This is how you see someone getting beaten during an arrest and people are like "but this guy was once arrested for such and such". The assumption…
It's a tough reality check for a lot of people who grow up in the US, thinking it's a free country with equal protection of the law, when they realize that there are at least two tiers of protected overclasses (wealthy landowners, and the police) to which only subsets of the law applies in practice (to say nothing of the underclasses who are routinely beaten, robbed, and killed, with no consequences for the attackers…
You say that I want to reject contradictory evidence, but you never provide the contradictory evidence. Having a bunch of people convinced that the police are evil isn't contradictory evidence. Having people repeat your viewpoint isn't proof that the viewpoint is correct.
For an extraordinary claim you need extraordinary evidence. For something like your anti-police sentiment (which is funny because now all of the sudden nearly all police are evil, in all states, all counties, no matter the gender or race breakdown of the police, no matter what city/county/state/department laws and procedures are, all of the sudden police are all just evil? That's curious isn't it?) it isn't backed up by evidence. You can link to videos alleging "police brutality" but none of them that I've ever been linked to show such a thing. Of course mistakes are made, when there's millions of interactions between citizens and police every day, a one in a million or even one in a billion mistake still happens, humans aren't perfect. But for the claims you're making there should be extraordinary evidence, and there isn't any.
Now, somebody else in the world will read your comment and in some part incorporate it into their viewpoint, and repeat it elsewhere, just propagating the idea further.