Should everything in the world be owned?
Private ownership is a right that is taken for granted by many in western countries.
Originally the concept was primarily used to deal with land ownership (at least that was the case in the USA during the days of the Revolution), but nowadays it has been extended to ideas, meta-data about ideas, and derivatives of ideas. In some extreme cases we see people considering future profits as a property that must be protected in the same way as any other private property
Needless to say, private ownership as it relates to material goods (let's leave intellectual property to the side for a moment) is a "right" that is bound to find limits because 1) people whose life depend on certain private property denied to them will attempt to acquire it and 2) even if nobody wants to acquire our private property, the world has physically limits and that sets a restriction to what can be owned.
I would argue that there are still a lot of material resources that are not owned by anybody. The air. The sea. Entire ecosystems. Think about technology that could enable us to extract minerals from the moon, or from the bottom of the sea, or gather energy from deep underground. Should we declare that everything that is not currently private property should be claimed by someone? And if so, should we take a civilized approach to this transition or should we use the old (maybe still current) rule of "the strongest gets the lion's share"?
What purpose does private property serve in a society?
Are there instances where there is direct conflict between the individual right to private property and the common good? How should that conflict be handled as a society, as a civilization?