So, people here are saying we already have xyz dangerous machine, but xyz isn't as scary. So let's imagine why this is scarier:

These things will be able to see in 360 degree multispectral/thermal/sound vision, and aim six arms at multiple people through walls simultaneously, never sleep, rarely need to recharge/eat, and have absolutely no empathy or mercy. They can aim and fire faster and more accurately than people, every shot can be a guaranteed kill, and they can be immune to gas/bio/etc weapons which they can release themselves. Nevermind the local terabytes and cloud petabytes of face recognition, AI models, social media profiles tied to street addresses, etc. They'll find everyone fast. Terminator was a joke compared. The next war is going to be insane.

People are in control of most all our killing machines now, but won't be soon. We did manage to stop using chem/bioweapons and nuclear weapons though. So maybe there's hope.

edit: when I say we won't be in control, I don't mean wild robots that won't listen to us, I mean we choose to run them on auto mode with no human confirmation before firing. I think such systems already exist on the Korean DMZ? (just auto guns, not robots)