I've got mixed feelings on this. I dislike cops as a general rule: I recognize that they are humans and the opinions and attitudes expressed by the police are going to reflect those of general society (some are nice, some not so nice). But I think that it isn't a direct correlation, because the average citizen does not have access to so much power and control over others. Thus if the cops as a whole have the same weaknesses and failings as the general population, they are going to be more instances of them abusing their power. Give the average Joe that type of power, and watch them abuse it. To be a good cop, you have to start with someone cut from a better cloth than the average joe. Unfortunately, the type of people who tend to want to be cops, are not the type of people you want being cops! You don't want a take-no-shit wannabe hardass, you want someone who is calm under pressure, can reason and influence people, diffuse situations, and communicate well with all types of people.
On the other hand, we have it a HELL of a lot better than people in a lot of other countries. Countries like Russia don't even have the court system to protect them should the police fail to do their job. In Russia, the courts are pretty much considered a branch of law enforcement, rather than a means to protect the citizens. We don't know how good we have it. The Russian judicial system has a 99.3% conviction rate. Either their cops are REALLY good at finding the right man (wrong), or the courts are just a rubber stamp on the police work. It's sad.
Now militarizing the police force is a big problem.