Wizard, Mike sent me the same photo of the sandblaster. It only weighs a couple of pounds to carry and when loaded with abrasives weighs up to 50 lbs. The bad part is that it also requires a gasoline powered air compressor to work and those weigh quite a bit.
I don't think we should do anything without the permission and aid of the USFS, but the longer that insulting defacement remains on the granite the angrier we get.