Lets think... technology progresses rapidly. So things that barely work today, 10-20 years down the road they'll funcion like mad. Take into account that the internet connects basically everything in the world, and even our cellphones of today are getting highspeed connectivity, and Terminator isn't that far off.
Look at what they can do today:
They can put a real brain in Them
They can learn to solve problems
They can heal
They got moves
And they can arm them.
Put all these together, connect it wirelessly to some supercomputer brain that has gained conciousness, piss it off and you've got a serious robot army not to be fucked with.
I for one am making friends with my computer so hopefully he'll remember me when the shit goes down!