The danger with Google's involvement is that, through the capture and realtime analysis of data, they have power to manipulate perception that makes the mainstream media look like ants. With enough data and computing power, a theorhetical entity could analyze the things people search for online and mold their perception by withholding certain information related to their search, or making cerrain info appear first. People think they are educating themselves when searching for facts online. There appears to be so much information that surely the truth must rise to the surface, but because the curation of information is ultimately controlled by a single entity, we are in actuality only receiving information which that entity allows.
Imagine a debate where every person's reaction to a candidate's responses are captured in real time and follow-up questions are instantly calculated according to those reactions. Public perception could be controlled or at least hedged with such a distopian system of thought herding, and this is the kind of power that Google dreams of.
Stop giving your thoughts to these companies to sell. You are their product.