One could write a book about all the different forms of legal trickery that have been used to expropriate lands from people who have lived on it for generations but don't necessarily have all the "proper" paperwork. Or even if they do. I live in a backwater in Brazil and I have seen lots of this. Even "gringos" are often victims because they don't know all the hoops you have to jump through to get the proper paperwork, and no infrequently the lawyer they hire turns out to be a thief.