What if it were programmed to recognize marijuana plants? According to an NPR story I heard this week, Columbia is shifting to manual uprooting to destroy drug crops, because spraying the revolutionaries' crops from the air is fairly ineffective and problematic both politically and health-wise. This is very dangerous work. Dozens of workers have already been killed, mostly by booby traps set by militants. Robots would probably be more expensive, but at least if they get blown up, no one has lost a family member.