Watch out for
The anti-anti-drone drone drones. That is the one that flies 'shotgun' for the real attack drone and takes down the anti-drone drone first, or just lures it away while the attack drone continues on its merry way to self destruction. All it needs to do is self-detonate when it detects pink (or any other colour) goo in the air, spraying anti-drone missiles in the right direction. This could be quite an expensive arms race.