In his sunny office on the edge of town in Arcata, California, Scott Greacen pulls up a slideshow on his large high-resolution monitor. As wildflowers sway in the wind outside a window, a woodsy guitar solo starts to play along with the pictures. Greacen mutes it; he wants to focus on destruction. Aerial images of clear-cut plots within the coastal forest, bounded by dusty roads and dotted with trucks, show the intrusion of industrial marijuana cultivation into redwood groves and hillsides. Some plots are small, barely detectable. Others cover hundreds of acres with row upon row of oblong structures covered with white tarps, blighting the landscape like giant predatory maggots.