Is this not open to manipulation then?
Well yes... but in the same way it is for Terraria (and Minecraft?), if you want to spoil your own experience of the game thats your choice. When it comes to MP it really depends on whether or not people want to be dicks or not. The world is huge so there isn't really that much you can do to spoil the game. Unlike Minecraft and Terraria where you can destroy things people created and raid content.