Dennis Sadowski at Catholic News Service  has a good summary of the moral and ethical concerns about drone warfare from a workshop at the annual Catholic Social Ministry Gathering. One participant, Charles Camosy, assistant professor of Christian ethics at Fordham University, suggested that it should be viewed as a pro-life issue:
"It involves violence and violent killing. It involves the killing of the innocent in a way that doesn't follow the church's teaching. It's an exercise of raw violent power in a way that I think should get pro-lifers really, really upset," Camosy explained to CNS.
“Marie Dennis, co-president of Pax Christi International, suggested that drones have led to 'a battlefield without borders.' "We have a global battlefield, which completely undercuts any possibility of talking about just war. There are no boundaries on this thing," she said.”
As the drone debate continues, it should go deeper into these concerns rather than only discussing legalities.