From the NY Times:
LONDON (Reuters) - Killer robots could become the weapon of choice for militants, a British expert said on Wednesday.
Noel Sharkey, professor of artificial intelligence and robotics at the University of Sheffield said he believed falling costs would soon make robots a realistic option for extremist groups...
"How long is it going to be before the terrorists get in on the act? With the current prices of robot construction falling dramatically and the availability of ready-made components for the amateur market, it wouldn't require a lot of skill to make autonomous robot weapons."