The dude is Redge Peterson. Along with the rest of his friends in Earth First!, he is blocking the entrance to a Forst Service building in Montana. Why: they want to stop the practice of logging of burned trees in a particular national forest.
Their point, I think, is that burned logs are supposed to be heathy for a natural forest. A forest, it turns out, enjoys having some of its bunch burned up every once in a while. Something about the natural decay providing a lush decaying material for future growth -- you know, nature's way and all that.
When they have sit-ins, I'm sure the cops just come and cart their limp bodies off for processing or whatever; so Redge has decided to stick his forearms into drums filled with wet cement.
What do they do with him now?