It's similar with Australia. The aborigines where here before the Europeans and had no concept of private property ownership. The land was considered to belong to everyone until the Europeans arrived and parcelled everything off.
There was nothing they could do. Aborigines were not even considered to be human beings until 1967. Until then, they were listed in the census under "Flowers and Fauna".
As someone who did an Economics degree I have a positive view of immigration. Immigrants increase the tax base in countries were fertility is declining and the population is aging. They also bring their savings to their host countries, which they spend, resulting in creation of jobs. They also tend to take jobs that no one wants or which cannot be filled. They spend their wages, which further increases jobs. It's not like every country has a fixed number of jobs that stays the same whatever happens.
