There's all sorts of legal issues. It's a minefield.
And in any case, there's huge PR exposure. And Google is ridiculously sensitive to bad PR.
I often get the sense the lawyers are running things, considering how often I've given up personally on ideas that involve data mining.
Not trying to be difficult, or troll.
What laws would this be breaking? The data they are gathering is proprietary and people have opted in to that data by using their services. Why shouldn't they use it to their financial benefit?