Well, I think the point is that the trees they want to "protect" are on gov't property (now, whether gov't should have ANY property other than that small amount defined in the Constitution is a whole other matter).
Nonetheless--the correct response to these tree-sitters is to go in and cut down all the trees except the one they are sitting in, go away until they climb down in disgust, and then come back and cut THAT one down.
Yep, and be sure to "ring" the sitters tree with the saw also. These watermellons use the tactic that it is unsafe to cut the trees they are in or near them because they might be harmed. Ringing is safe and finishes the tree, thus making all the watermellon training and activity fruitless (sort of).