Most Native Americans believed, in years long past, that nobody could own the land.  Hoever, when they were threatened by increasing numbers of settlers taking up residence in their home territories, they fought to keep it, so obviously they did feel it was "theirs".  People these days like to own land and homes of their own, as well as other material goods, but the truth is, you only own something as long as you can keep it, whether by legal means or by force.

The Government can ban something you legally possess, and take it away from you.  They can decide you have more than you need, and take some of your wealth away in the form of taxes, to be spent as they decide best on others.  They can also take your land by using a power called "Eminent Domain" if they decide a greater good is served by that land being used in a different way.  It used to be used onloy only for things like the building of roads or railroads, but increasingly it is being used in cases where letting a developer build a store or other commecial enterprise will bring in more tax dollars for the Government.  The link below is to an article that deals more extensively with the subject.