When Appropriating Property, Locke Says One Can Take as Much

When appropriating property, Locke says one can take as much as one wants as long as __________.

A) One calls it first
B) God allows it
C) There is as much and as good left for others
D) One agrees to let others use it
E) g. everybody. But also, since God gave the earth to everyone equally, no one can appropriate something to the degree that it causes harm to another, in other words, no one can own more than what he really needs. After this, he is taking from the share that properly belongs to others. This may be problematic. One may think it is unreasonable, for it is difficult to determine who may have put the most amount of labor into a thing. Take for instance a guitar: is it the property of the person who has made it, or the person who plays it the most often, or the person who plays it the most beautifully? One may, however feel that it is a very reasonable assertion to own what one has put the most labor into. It certainly has a very intuitive thrust to it. We often speak of things which we have put our blood and sweat into as being a part of us, and it certainly seems less reasonable for someone to own something which is never made useful, and which they have no history with, other than ownership.
A further complication may be exemplified by the American theft of land from Native Americans. Certainly from the perspective of European Americans, the land was often worked on more and put to far greater use. But use for who? The land may not have been labored upon for crops or industry, but Native Americans certainly resided and lived of or it. So which claim is on the land is the more moral claim?