I recall the time I was scolded for my avatar being a Chihuahua humping a stuffed animal, because this was a family site and people's kids might see that. I guess it's an adult site now.
I agree that the vast majority are entering the force with good intentions. But the pervading culture completely negates those intentions. Even if all that happens is they turn a blind eye to abuse, they become implicit and they violate the oath that they take to uphold law and order.
I'll take this further...
The other teachers know about it, cover it up, brag about it, do it themselves, and a sizable portion of the citizenry deny that it's abuse and then slap stickers on their car representing the abuse.
The thin blue line represents the blue wall of corruption. It represents solidarity between police officers to not turn each other in for their abuses.
It's funny when people use the "one bad apple" analogy in an instance of abuse of power by a police officer, because they never use the whole saying. One bad apple spoils the whole bunch.