An anonymous reader writes: You can add terrorist-controlled drones to the list of dangers we need to be prepared for, says the Oxford Research Group. Its new report contains information about over 200 current and upcoming unmanned aerial, ground and marine systems, and evaluates their capabilities for delivering payloads (e.g. explosive devices), imaging capabilities (e.g. for reconnaissance purposes), and their general capabilities. Even though the report notes that commercial drones have a limited flight time, range of movement, and payload capacity, and that their operators still have to be relatively close to a potential target, the researchers are particularly worried about the possibility of drones being used as remotely controlled explosive devices. They say, "The technology of remote-control warfare is impossible to control; the ultimate defence is to address the root drivers of the threat in the first place."