Just read this article on the BBC website and it made me smile...
Robot-inflicted injuries studied
I can't imagine that household robots with dangerous items will be introduced until AI is in such a state that it can clearly tell the difference between normal people, pigs and perps.
Then again, ED209 was supposed to be a clever cat and looked what happened to him! Execs dead and it can't even get up and down the stairs. Then again, a useless executive killer is probably what we need right now after the banking crisis.