I’ve spent years thinking the issue through. It’s not just the drone swarms, there will also be humanoid (more like gorilla-oid) machines which move faster than the eye can follow and punch through walls. Not decades from now, but within ten years for sure, five years possibly.
Jamming bandwidth will work initially, until they become fully autonomous. Passive defenses (stone and steel) will be of value, initially, until the machines become clever enough and powerful enough to rapidly disassemble just about anything. A shotgun with hardened slugs will be of value, initially, until the machines move too fast to see and have vital areas covered with armor. Despite the obvious tendency to create collateral havoc, EMP may be of value, initially, until the machines become hardened to it.
All passive defenses are doomed to fail, including living underground. EMP and firearms will not save us. The only realistic defense against fast and deadly machines long term, is other fast and deadly machines.
We could try talking to the Slaughterbots. Is it a proper noun now? I dunno....
Maybe they just want what’s best for us. Like politicians do. (P intentionally p’d).
Self driving car bombs are likely to be more of a problem. ISIS used manned suicide car bombs effectively against ground forces, even armored forces, until sophisticated missiles and air power were available as a countermeasure. Large numbers of autonomous car bombs would be very hard to detect and defend against.
When autonomous vehicles go bad it won't be pretty.