Two differences. (1) You can do more targeted attacks. The furthest IRA got was usually to park a van in front of a building. With drones, you can target indivi

Two differences. (1) You can do more targeted attacks. The furthest IRA got was usually to park a van in front of a building. With drones, you can target individuals, cars, planes, etc, even when they are physically separated from public spaces. (2) Since you can do targeted attacks, you don't need that much explosives. This makes you harder to identify and track. Breivik had to buy a farm to have access to the amount of fertilizer he wanted to use.