One thing anyone can do (has a right to do) is defend themselves, that's the most basic right, that no one can take from you. (with one exception of course and that is when you aggress against others. So no laws that say you may not have a gun or may have a gun if you have permission from the masters/rulers. ( In america you still have the second amendment here in europe, in some country you get a fine if you carry pepper spray smh)

But that  in and of itself would make it unattractive for criminals  to go around, steal and murder, because the risk of meeting some one with a gun and getting killed is much higher with an armed population.

I go on to the army question know.

Can you imagine that it would be very hard for a country (if they still exist then) to go from door to door, to invade large piece of land (what previous was called country)
It's much easier to invade a land and take over the system than if there is not such a system.
Going from door to door would be very risky with people that are armed and have communication in one way or another.

But now organization.
If you don't want, or can not defend yourself, then people could hire "police". But then " police" would only have rights that you and I also have.

 Dale brown in Detroit is one example on how it could work I can also imagine security firms  like you have now, or maybe an neighborhood watch. Or a gated community.
There are lot's more idea's where I might not even have thought of.

Instead of an army there could be militias that you hire or maybe work in.

You could work with insurance firms and there could be private courts. Which is nothing more than a third person that you both trust that you could hire. 
It could be that those firms have ratings like on amazon is on thing I can imagine so you can see which are trustworthy. But it can also be as  simple as, just a normal person, that is trusted, in a town or  community, or what ever, that gives his opinion. Because what is a judge other than a normal person that gives his opinion.

I will get back to you with some video's I have to search on the net.

Oh firefighters......... could be volunteers, just like now, or payed private  firefighter firms, 
or crowdfunded......
But what if someone has no contract with them, are they gonna stand there and watch the house burn down? Is a question you get a lot ;)

Well here I can imagine a few things.
They put the fire out and send a bill later or they sign a new contract that has higher fees, like insurance.

But maybe  that if I as a neighbour have a contract, and if there is a danger that the flames go to my house, they might put out the fire anyway to prevent other houses from burning down.
I personally would pay for them even if that danger was not there or chip in afterward if they got a bill.
There could be a possibility of charity. 
I can also imagine that some don't even want a contract but want to have their own sprinkler installation or whatever.
There are probably way more idea's than I can think of, and then again, I don't have to write a master plan for the whole world, before I can be free ;) 

But I like to give people some idea's I've thought of and have come across.
I know it's not easy when you must think about those things because daddy and mommy government have always don it for you 
You could see it so that we have been kept children, and for a reason and that reason is control.
Being a free adult individual  asks form you to take responsibility for yourself and for your surroundings. It can seem like a lot of work, if you have never thought about it And before I became an voluntaryist I had never thought about these thinks. But it has to start somewhere.

[Larken Rose just wrote this article a day ago which talk also about this stuff from an other perspective.](https://steemit.com/anarchy/@larkenrose/if-murder-were-legal)

I'll get back to you with some articles/video's..... can take a few day's though.

Peace :)