Buildings get generated over / item cloning and lag
If you build close to the edge of the currently generated map, the map generator, when it catches up, will generate over your building. I lost about a stack of cobble that way. I checked my inventory, and the cobble is completely gone.
Maybe building/digging should be disallowed in the edgemost chunks, to prevent this sort of thing.
Speaking of edgemost chunks, if someone goes all the way to the edge of you world (after all generation has taken place), and throws an item off the edge, it will fall a ways, then begin to clone itself repeatedly. The player can't go get the items, as they can't jump off the edge themselves, but having lots of items causes a lot of speed reduction of the server.
Perhaps items should be kept within the bounds of the world, the same way players are.
Maybe building/digging should be disallowed in the edgemost chunks, to prevent this sort of thing.
Speaking of edgemost chunks, if someone goes all the way to the edge of you world (after all generation has taken place), and throws an item off the edge, it will fall a ways, then begin to clone itself repeatedly. The player can't go get the items, as they can't jump off the edge themselves, but having lots of items causes a lot of speed reduction of the server.
Perhaps items should be kept within the bounds of the world, the same way players are.