What you do is you work out the hours your problem neighbours are asleep and hopefully hung over, and co-ordinate with your fellow victims to blast some obnoxious music full bore from every house that surrounds them, the exact same song on infinite repeat for maximum aggravation. You all go out for a beverage for the next several hours so none of you are there when fat bastard comes and pounds on your doorways.
We did this several times, and our problem neighbour generally kept quiet after that. If she forgot herself, we'd put 'Bat Out of Hell' on full bore, and it usually only took the first three bars before she shut the fuck up and everything was peaceful again.