This happens in a lot of countries and is a problem. That doesn’t mean that rights to private/personal property aren’t guaranteed by law in Australia, just that

This happens in a lot of countries and is a problem. That doesn’t mean that rights to private/personal property aren’t guaranteed by law in Australia, just that the law is skirted by monied interests. The farmers you talk about would likely be able to fight this in court if they had means - but such is the nature of late capitalism, money buys you political power and legal clout.