Land rights and ownership: how do we decide?

This one might be controversial, but brings up the question: Who really owns the land? If someone cheated, killed, stole in order to make money to obtain wealth to buy land—do they deserve it?  Here is a video about the MST movement in Brazil to stimulate your thinking and invite discussion.

http://www.youtube.com/watch?v=56ovNOytyzQ&feature=related

History of the MST More food for thought. Will we starve because people own land and do not use it? In the Brazilian constitution, if land is not used, then it is up for people using it—is that more of a true property right than buying and selling land for outrageous profit, or holding onto land just in case you might need it—while people are living in cities with meaningless jobs, or homeless, or suffering in so many ways because of lack of land access? What do you think?

http://www.mstbrazil.org/?q=history