Most people never think about where property rights come from, and when we have an alternative view of property slapped in our faces, it can knock us right down. Think about the stereotypical hippie character in some bad '60s movie screaming "Property is theft!" What the hell does that mean?
I always thought it was a socialist/Marxist thing until I started reading about anarchism a year ago, and discovered the phrase sprang from the pen of Pierre-Joseph Proudhon, the first person to call himself an anarchist. He also wrote that "property is freedom," because he knew about consistency being the hobgoblin of small minds.
What he was getting at, in those simple little phrases, was that he, and most anarchists and socialists since him, don't agree with the way property rights exist in our current society.
Thought experiment: You own one (1) acre of land. By what right do you own it? Well, you bought it from the guy who owned it before you. And he from the person before him, and so on. But in North America, those chains of ownership aren't very long. Eventually, we find someone who settled empty land, or actively swiped it by kicking out/killing the natives. And in Europe or Asia or Africa, you see the same chains of ownership, interupted by occasional theft by men armed with rifle, musket, matchlock, halberd, broadsword, gladius or pointed stick, as appropriate to the era. All land occupied by humans was stolen from other humans at some point or another, and the paperwork was filled in later to make it look like a legal sale. It hardly seems like a reliable basis for a system of ownership, does it?
To replace this system, usufruct has been suggested. Simply put, it means you own what you use. When you stop using it, you cease to own it. If you find unused land or resources, you can start using them yourself. Murray Bookchin, an eco-anarchist, put it this way:
"the principle of usufruct, the freedom of individuals in a community to appropriate resources merely by the virtue of the fact they are using them. . . Such resources belong to the user as long as they are being used. Function, in effect, replaces our hallowed concept of possession."
Usually, radicals like to scream slogans like "Property is Theft!" without explaining what they would replace our current system with, which is just bad public relations. If you think about usufruct, it doesn't seem that bad. You live in your house, play lawn darts in the back yard, plant a little garden? You own it, and the community will support your ownership of it, either through some sort of free-market court system or a voluntary jury. The same goes for your car, your wristwatch, your iPod, your dog, your socket wrench set, your collection of small bits of string in the junk drawer.
If you rent an apartment or a basement suite, congratulations! You now own a portion of the building, and are essentially a member of a condo association or part owner of a home. If you are a landlord, you are SOL. If you're lucky, the new owners will hire you as the maintenance guy.
But how do you establish a claim? How long does it last after you wander away? What if you want to go on a six-month trip cataloguing butterflies in Brazil, and when you come back you find that some dirty hippy has moved into your house, because you weren't "using" it? This is one of the thorniest problems of usufruct, and I suspect it could only be worked out, somewhat imperfectly, by trial, error, and the creation of widely-acknowledged custom or common law.
Probably the easist way would be to estalbish community claims offices, like the offices that monitored and licensed gold panners in the 19th century. If you find a vacant house, the first thing you do is wander down to the office. Is it really vacant, or has the owner just forgotten to mow the lawn, or gone on vacation for a few months? If it is vacant, register your claim and move on in. To cement your claim, you should, as Locke urged and old American common law had it, mix a bit of your labour with the land. Fix the place up a bit. Mow the lawn. Plant some carrots or tulips. After a week or a month, the claims officer will wander by, see what you've done, and put a check mark next to your name. Home filled, usufruct-owner in place. (Anarcho-capitalists would no doubt see the claims office as a free-market, for-profit business, possibly with several competing officers, and the collectivists would much rather see a community effort to register property use/occupancy, but it amounts to the same thing in the end.)
Practically, the biggest hurdle to usufruct is probably cultural. We are very used to seeing property as a concrete thing that can be picked up and put down, left alone, but which is still attached as if by invisible threads to its owner. The idea of property without an owner is frightening for some people. A few decades ago, some anarchists in Holland started leaving white bicycles around Amsterdam for anyone to use and then leave when they were done. The police kept seizing them as "stolen property."
The neo-conservative view that private ownership of every resource would provide a better degree of stewardship than any kind of government or communal ownership also rears its head in this discussion. I really can't say just how ridiculous I find this idea. Let's leave aside the fact that a corporation with a five-year financial plan could easily strip mine or clear cut land to fulfil short-term shareholder demands, and look at the example of public parks. I mean small, community parks, with swing sets and a few sports fields. Would you rather they were owned by a private individual for profit (lots of billboard ads, or pay parking, or even paid admission) or by the park users? Sure, there would be lots of free riders, but a community parks group could probably handle keeping things in order pretty well.
In my final note, I'll say that many right anarchists and libertarians believe in something much like the current property rights system. But without a government and police force to enforce property rights, usufruct would become the only method of property distribution. Any private security force that defended someone's right to forbid use of unoccupied land would be a de facto government. And any collectivist group that walled off a section of "their" community "for future use" and stopped others from encroaching would be doing the same thing. And don't think people wouldn't try it.