WORLDGUARD-2258 - Reported by Aragoth

i have a region where user can buy 20x20 regions...
when they use a piston
they can move blocks above their bought region... without the permissions
so they can grief other regions of users and destroy other buildings.

When users build a sand/gravel cannon to shoot sand/gravel, they can shoot on other regions without the permissions and the sand will placed there : /