"While we do not believe that UAV strikes cause disproportionate civilian casualties or turn killing into a "video-game," we are concerned that the availability of lethal UAV technologies has enabled US policies that likely would not have been adopted in the absence of UAVs. In particular, UAVs have enabled the United States to engage in the cross-border use of lethal force against targeted individuals in an unprecedented and expanding way, raising significant strategic, legal and ethical questions."