In the next decade, US defence spending on known medium- and large-size unmanned aircraft will be nearly $40 billion, increasing inventory by 35 percent. Ranging in size from a private aircraft to a commercial jet, nearly 800 of these bigger unmanned are operating around the world, observing, collecting data and in some cases attacking the enemy. The military also has thousands of mini-UAS used for battlefield surveillance. Since 2001, the US government is estimated to have killed more than 2,000 militants and civilians in UAS attacks.
Source: The Washington Post