Do you know how the USA, colonial powers property, farming, logging barons and oil tycoons acquired their land and wealth?
Most people from Rich family that own massive tracts of land acquired their wealth in the same way.
Its no different then the industrial Tycoons of today whose families wealth was built of the back of land theft and slave labor (you will be surpised just how many people owned slaves and no it was not just simply the rich people.)
At one point if you were a war widow you would be suggested to invest your pension into owner several slaves and the return on there work would increase your return. So normal people were slave owners as well also a fact.
The crimes of the past are not now crimes of the present, otherwise you would need to seize ALL PRIVATE land and make it state owned because it was most likely at one point or another stolen from someone to begin with.
Roman invasion, de-landed the native tribes, Norman invasion de-landed the anglo saxon land owners so basically no one today should own the land because it was most likely stolen in the first place.
The nations of the USA is basically a stolen land as is Australia but i doubt you would argue that people in those countries should be stripped of their land to return it to the decendents of the natives?