i) They are generally very nice people who ensure that some modicum of law exists in society, and many a time they are heroes in every sense of the word.
ii) However, at the same time I am cognizant of the fact that they are human, and that just because someone wears a blue-suit, carries a badge, and open-carries a fire-arm, does not mean that they are as white as hysop. A cop can be just as dirty as any perp on the street, with the only difference being that the perp on the street has to watch out when they break into your house. A cop can simply go in through the front door, while the perp would probably try and jig a window in the back.
Thus, most cops are good people. However, there is nothing intrinsically present in a cop's badge that makes the holder of one immaculate. No oath can do that. In my profession (fund management) one of the highest milestones is the CFA designation, and one of the key cornerstones of it is ethics (one can get kicked out for the smallest infringement). However, that doesn't mean that there are people who are not ethical. Sadly, there will always be humans who do bad things.
And until the day that people who become policeofficers come fluttering down from heaven on angels' wings, there will always be some cops who will be worse than perps.
I collect NFA firearms. I have had many transfer and registration forms signed by the sheriff, and I always assumed there was some record of those forms kept by the sheriff's office. With those, they could potentially determine that I was "heavily armed" with "military-style weapons," thus necessitating a SWAT team dynamic entry at 2:00 AM. When the door's bashed in and flash bangs are going off, nothing good would come of that.
I can only thank God that didn't happen.
But the fact that they can get a signed search warrant, with no more investigative effort done than to take the word of some out of state bounty hunters, not even taking the time to cross-reference my address with the latest phone book or property tax records, should frighten anyone.