Wow, I had no idea cop shops kept Nixon-style "enemies" lists.
Whether they are official lists or just unofficial tallies maintained by the officers, I have always believed that police departments keep such lists and it is why I would never allow my name to be used in (for example) a letter to the editor that's critical of a police officer or department. If they decide to "take in interest" in someone, there are all kinds of ways they can make your life "interesting."
Police departments can't be trusted to maintain lists, even for legitimate purposes. Several years ago, as I was sitting at the computer one evening, the phone rang. I answered, and a rather gruff voice on the other end said, "This is Dispatcher ___ of the police department. You need to bring your dogs inside the house RIGHT NOW so the officers can approach your door."
Well, this was certainly news to me, because (a) I didn't own a dog and had never owned a dog; and (b) I could see the driveway and there were no police vehicles in sight. So I informed the dispatcher of that. Whereupon he escalated his tone of voice (obviously he had attended "command voice" class) and told me in no uncertain terms that if I did not comply with his order the officers would have to shoot my dogs and break down the door.
I invited him to fire at will, since it was obvious he had no idea who he as calling and I was certain some family would be only too happy to file a lawsuit against the municipality and the police department.
Naturally, it turned out the officers were at the home of another family with the same last name, at the far end of the street. That family had an unlisted telephone number -- and multiple German shepherds. Turns out the geniuses at the PD got "their" number by calling directory assistance. Since the last name isn't exactly Smith or Jones, the operator gave them my number even through the street number wasn't even close, and the idiot police never bothered to verify it.
And now they want to start keeping secret lists of dangerous addresses? I think that's a monumentally terrible idea.