We use the "areas" mod for protection. Each area is an invisible cuboid which is owned by a player. To create an area, you need to do the following: At first, type /area_pos set1 and punch a block in one of the corners. Then type /area_pos set2 and punch a block in the opposite corner. Note that the area is three-dimensional, so one of the corner must be on the bottom of the area and the other corner must be on the top of the area. Make sure that the walls, floor and roof are also inside the area. If you placed one of the points wrongly, type /area_pos set1 or /area_pos set2 and punch the node again. After you are sure that the bounds are correct, type /protect <area name> where <area name> stands for the name you want to assign to the area. By default, you are allowed to create up to 30 areas up to 64×128×64 blocks in size.
If you are inside the area, a little notice appears in the bottom left corner. It displays the area name, area ID and area owner. If you need to do anything with the area, you will need to know the area ID.
Simply type /remove_area <area ID> where <area ID> is the ID of area you want to remove. If the area has any sub-areas, you will loose the control over them after deleting the area. Better delete all sub-areas first.
Type /add_owner <area ID> <player name> <area name> where <area ID> stands for the ID of area you want to add a new owner, <player name> is the name of the new owner and <area name> is the name of sub-area which will be created. This command will create a sub-area which will be owned by the new owner. When there are more areas somewhere, a player can dig or place blocks when he is an owner of at least one of the areas (or one of the areas is open, see bellow).
If you want to remove the player from the area, just remove his sub-area.
If you decide to remove the area completely and it has more than one owner, you need to remove all sub-areas first. If you don't remove them first, you only give up your ownership while the other owners will still own the area.
Type /change_owner <area ID> <new owner> where <area ID> stands for the area ID and <new owner> stands for the name of the new owner. After doing this, you will be no longer the owner of the area.
Use the commands /area_pos set1 and /area_pos set2 as if you wanted to make another area in the new bounds. After that, type /move_area <area ID> where <area ID> is the ID of area you want to extend, shrink or move. The area will be moved to the new bounds you marked.