Suicide drones
Its not if terrorists launch attacks with swarms of suicide drones.
Its when.
“All of this seems to underscore that, if the PLA doesn’t have an operational drone swarm capability, is getting ever closer to fielding one. A swarm that can be deployed from multiple platforms, on the surface and in the air, potentially approaching a target area from multiple directions, would give the complete system immense flexibility and resiliency.
Swarms are inherently difficult for opponents to defend against and one of their most obvious applications is to blind, confuse, and overwhelm enemy air defenses. This very real threat is something The War Zone has been sounding the alarm on for some time now.”

Modern day assassins will never need to leave the house.
“Being networked together, and being autonomous in nature after being loaded with a target area location, along with other mission parameters, these swarms will be extremely hard to defend against using even the best SHORAD [short-range air defense] systems in development today. It’s the saturation nature of the attack, the size of the attackers, and the fact that they work as a coordinated swarm, employing dynamic tactics to see as many in their company survive long enough to make their suicidal attack, that makes them so deadly… Just the knowledge that such an attack is possible would be psychologically stressful and demoralizing for troops on the ground.”
The game of cat & mouse is endless.