Mentally, I keep track of "difficult" people. Yes, I've encountered the usual crowd -- the senile old-timer that thinks they own the town because they've been here since 1928, the folks who come in to argue for the sake of arguing, consistent code violators, the militant LIbertarians, the race baiters, and so on.
When I delivered pizza in my undergrad years, the drivers used to keep track of the tipping patterns of various addresses, gpoing so far as to incorporate some primitive demographic analyses in the process. (Yes, pizza drivers do "profile.") What good did that list serve? UB students tipped well, Daemen students stiffed all the time, residents on a certain block in Amherst all send their kids to the door as a sneaky way of stiffing, and the elderly still think that 25 cents will buy a round trip streetcar ride downtown for you and your sweetie, where you can both catch a movie, get something to eat afterwards, and have enough left over to buy a new suit the next day. That's all good, but aside from tracking those patterns, the "profiling" really didn't accomplish anything.
What purpose would be served by keeping a written list of citizen nuts?