Everything is voluntary, therefore laws are useless. They may exist, but no one can be forced to follow then or be punished for not following them, therefore they are useless and effectively do not exist.
I think I finally see what the problem is. Everything is voluntary, but more importantly, everyone will do everything in their own self interest. That second part you're all ignoring, and is the part that will keep a business from screwing their customers, a security company from extorting their clients to the point where they become unproductive, a nuke company from selling products that destroy the people paying for those nukes, private courts from screwing customers and making decisions majority will consider unjust, etc. Everyone has their own version of property and contract law only to the point that they have their opinions on those laws respected by others. If everyone agrees it is just, it's a law until they don't. If everyone agrees to spend their money at a place of business, if is in business until they don't. If a business agrees to follow the contracts and rules established by other businesses in that market, it will continue to be able to do business with the customers and suppliers in that market until it stops. There is no law that says you must buy your stuff from Wal-Mart or Target. No law that says Ford must buy their tires from Firestone. No law that you must use arbitrage if you buy your cell phone service from AT&T. But if you or they do, they must agree to the contracts they have signed, with pens and dollars, or be thrown out, lose parts suppliers, or lose their service.
The fundamental part of libertarian greed and self-serving, as I understand it, is doing as much as you can to get as many others as possible to give as much as they can to you. If you want to come up with examples of how THAT will be a problem, feel free to. Likely I may join you. But as mentioned too many times, other people's money and production capacity is what keeps all the strawmen mentioned so far in check.