Home Owners Associations were designed specifically with this in mind. I used to hate the idea like I hate communism or anything with the word Hillary in it, but I've realized that I'm exactly the kind of person who is best protected by them. I'm a good neighbor and I want maximum appreciation and minimal risk of erosion in my community standards. HOA's are private organizations which get government sanction to operate and they do with governments cannot or will not do but often should have been doing all along. (If you are going to flame me about HOAs, save it. I already know the solution to every problem you will propose.)
No flames. HOAs can protect people from the mess we've been talking about above. The police won't. The only gripe I have about HOAs is that it's like paying protection money every month on your own property, and the fees seem to go up, up and up every year.