Good news, everyone: Google is looking out for us! It doesn't want a cleaning robot to knock over grandma's vase. For some strange reason, the researchers chose to illustrate these dangers using the example of a cleaning robot and not a sentient superintelligence that wants to enslave us. In terms of elegance, they don't hold a candle to Isaac Asimov's Three Laws of Robotics, but I suppose that's to be expected when you're writing an academic paper and not a speculative science-fiction novel that doesn't actually have to obey the laws of physics. Maybe the cleaning-robot examples make sense given that Eric Schmidt doesn't think very highly of AI fears.