[mikk0j]

The blogger who wrote this up as terrifying isn't really with the program. With a friend of mine building laser-guided mosquito zappers in her backyard, drones like these are relatively easy to deter. Of course it leads to an arms race, but maybe we'll eradicate those mid-summer bloodsuckers while we're at it.

Drone proliferation, military and civil, is unavoidable.

[dredmorbius]

It depends on the cost of developing weapons, the cost of countermeasures, the relative effectiveness of both, and target selection.

Shielding high-value targets from ultra-small drones would be relatively easy. For someone bent on terror or softer targets, it's harder, and the attacker need only succeed once (or a relatively small number of times).