In my opinion, the idea is not bad, but it is doomed to failure. All parts of the planet have long been distributed among states and are controlled, and this will already be a violation of rights.
If they collected enough fund they can just buy these pieces of lands and own the rights on that property. I do not think that this kind of thing will bring a violation of rights as long as all is processed in legal ways. We do not need to barge in and say we own this land, we can just all act as a responsible law abiding adult and buy land that is owned by other people if they agree.