I sincerely hope so; pirating anothers CPU cycles should be as much a crime as, for example, tapping in to a water line paid on someone else's bill, running up another's phone charges for personal use, or draining another's electricity. It is more deeply criminal to deny others the fruitful use of a viable communication line by glutting it with irrelevancy and offensive, deceptive material, but that may be beyond legal definitions at present.

A