Give the power to the players, and a natural evolution will take place to set everything right
That way the players adapt to griefers by making traps etc. etc.
Also... Instead of blocks, it would be cooler and more innovative to use voxel terrain, with different material properties.
Dirt would be easy to destroy, wood shouldn't be easy to be destroyed with your bare hands and stone should be impossible and might even hurt you.
If building materials(raw tree) needed to be cut into smaller pieces etc. etc. there should be an innovative crafting system, which I would love to design
Crafting is my life, it's SO fun!
I could be great if there were some kind of physics to the voxel terrain, and with the increasing computing power of the future and today, the problem isn't as large as it was before.
Let me draw you an example really quick
Here's the image
the attachment doesnt work -_-