I personally suspect the ethics board exists for more prosaic reasons. Think "don't bias the results of people's medical advice searches to favor the products of pharmaceutical companies that pay you money" rather than "don't eat the world".
EDIT: just saw other posts including quotes from the head people of the place that got bought. I still think that this is the sort of actual issues they will deal with, as opposed to the theoretical justifications.
So I know we've already seen them buying a bunch of ML and robotics companies, but now they're purchasing Shane Legg's AGI startup. This is after they've acquired Boston Dynamics, several smaller robotics and ML firms, and started their own life-extension firm.
Is it just me, or are they trying to make Accelerando or something closely related actually happen? Given that they're buying up real experts and not just "AI is inevitable" prediction geeks (who shall remain politely unnamed out of respect for their real, original expertise in machine learning), has someone had a polite word with them about not killing all humans by sheer accident?