I'm glad you asked. Us libertarians debate such things amongst ourselves in order to find solutions. For your dilemma, we have given our libertarian stamp of approval to deeded communities.
In such a community, you would contractually consent to not do things that would disturb your neighbors. If your neighbor violated his contract and started having crack and hooker parties on his front yard in front of your kids, he would be guilty of fraudulent breach of contract, and you could have him evicted, and damages done to you would be remedied in civil court.
This solves your problem without resorting to 3 AM Paramilitary style assaults upon your neighbor, and possibly yourself, if they get the wrong address.
Oh, and all those prison guards that would have guarded your neighbor in jail for the next 10-20 years would have to go get real jobs. The money you save in taxes for their salaries could go back into your neighborhood if you like, to make it a nicer place. Maybe you could spend it on a nice new park for your kids in the spot where your crackhead neighbor used to live.
Whattd'ya think?