It's a tricky ethical area. The Google post cites several research papers that seemt o provide more than enough information to replicate these results or get similar ones, which is good, because I think everyone should be able to explore these tools - I stick by my view from yesterday that this may be a scientific breakthrough.
At the same time, I can see the basis for some anxiety, because it's not hard to imagine proprietary research going a few steps farther and developing some sort of general intelligence or even a limited but extremely high-powered intelligence that would confer an overwhelming commercial advantage, and/or a political one. Suppose, as an exercise, that one developed an algorithm to maximize persuasiveness by first leading readers/listeners into a quiescent, semi-hypnotic state and then making your commercial or political pitch. There's certainly a potential for abuse.
In Europe this sort of thing tends to bring up the precautionary principle, the idea that you shouldn't do something without oversight and demonstrated minimization of risk. I think that's highly limiting, but expect some pushback against Google over this. Of course, I don't think democracy is all that wonderful either but then I'm a bit of a misanthrope.