I can see it now: just get the enemy to breathe in a cloud of nanobots, or have the bots enter their body through an open cut that they make, and the enemy’s body is yours: no violence needed.
We live in a terrifying time because there’s just no way to dodge this sort of stuff unless you have the EMP tech, since a Hazmat suit is unsustainable to don long-term.
Also how is this different form just gassing the enemy?
Astronomically more complicated and expensive, therefore cooler.
Also, you can’t EMP gas, though I guess that’s one the smallest downsides of nano robots.