True job creation. This would create whole new specialties in the fields of legal, insurance, adjusters, accounting, police training, programmers.... Just a few off the top of my heavily medicated head. I can give reasons if anyone thinks "no," but I think these are pretty obvious.
I see protocols developing. Some will allow swarms of tiny (probably the size of peas), flying PDBs (Personal Defense Bots) to safely interpenetrate each other... say as if on a crowded sidewalk at Noon in the business district. There will be protocols for different PDB swarms in such a crowd to cooperate together to collectively protect the entire "herd" from the predator.
PDB weaponry would probably include: - a shocker/stunner (simple capacitor), - a "kamakazi" emp generator to take out enemy PDBs (probably Phlebotinum powered :grin:), and
- a tiny explosive charge for kamakazi ramming drama.
The first and third are also effective against human prey.
Bad guys might have their own swarms, armed with NBC agents of assorted deadliness, as well as the above.
Imagine ICBMs with payloads of such microbots. No mushroom clouds. The missile just shoots out hundreds or thousands of tiny missiles all of which deploy airfoils and float in the winds... and then release millions of those Bad Guy microbots.
Scoff at pea-sized bots? Please research the curve followed by the "transistors per square mm" metric. And follow the [tons of] money. I rest my case.
But wait! There's more! Let's go CELL-sized. Scoffing again? Back in 2014, scientists at the University of Texas built and tested a working motor
small enough to fit inside a cell.
http://newatlas.com/nanomotor-for-nanobot-drug-delivery/32160/
Understandable fears aside, consider the medical value of having millions of (super-well-controlled!) nanobots cruising through your body in constant search of something to fix. They might even eventually be able to do things like weed-out cells that are going cancerous. Or possibly do nanosurgery and zap out with a CRISPR tools the chromosomes that mutated and caused the cell to go cancerous.
They might be able to help out with that nasty, repetitive job (almost literally like laying chemical bricks) of rebuilding the telomeres that cap the ends of chromosomes.
You might want to think a bit about the implications of that.
Their ill-effect on you would be a tiny increase in weight and a small increase in your calorie intake (the nanobots get power from chemical reactions that, in effect, steal sugar from your cells. You eat more to compensate.
You could consider them the nano-sized equivalent of the man-sized android prototypes being created right now by DARPA and Boston Dynamics (among many others). Those androids - Big Dog, ASIMO types, maybe spider types? snake-types? - might serve a shock-troop support function for flesh and blood soldiers.
The nanobots will be the shock-troops for the body's white blood cells, the lymph system, and certain other critical life-support systems.
Imagine a soldier with a nanobot-packed body.
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My answer - everyone has bots - is the only answer that works. Because sure as chit some azzhole running some chithole country somewhere is going to see this technology as a way to World Emperor-ship. Unlike nuclear bomb technology, this kind of technology is freely talked about all over the world. Millions or even billions will die.