Attempts at dropping handguns in prisons with commercial drones have been attempted before, but this is the first time a hand grenade has been used with drones, in an offensive setting. How Daesh is arming the grenade, or even dropping it is somewhat confusing. The drone is possibly being used as a sort of “Kamikaze” Drone, driving it into a target, allowing a grenade with the spoon detached to detonate when it falls free of the drone. Drones have previously been used by Daesh to film their own attacks, as well as spying on Iraqi lines. The below video shows one these drones getting shot down by Iraqi forces.
Iraqi forces have also been using drones of their own to likewise spy on Daesh positions in the fight to recapture Mosul.
When I was in Afghanistan in 2014, there were some substantiated stories by some of the drone operators in my platoon about MARSOC using Honeywell RQ-16 T-Hawks to drop grenades on Taliban positions. How true that might have been, or even if it happened at all I’m not sure of, but the stories were certainly there and came from credible sources. Much like most of what happens in Special Operations, it will probably come out 10 or 20 years from now.