If you'd like a scholarly explanation of how the process works, I recommend Zeynep Tufekci's "Engineering the Public: Big Data, surveillance and computational politics." That's an article right out of my Class Reader in my course on "Privacy, Technology, And Freedom."
Nothing that Congress can or will do to Facebook will change the political reality we now confront. A pertinent article in the Washington University Law Review, entitled, "Privacy, Poverty, and Big Data: A Matrix of Vulnerabilities for Poor Americans," points out that the poor are particularly disadvantaged by how big data is now being manipulated. Hey, what's new? The poor are almost always being manipulated (more than those who are better off), so it's no surprise that this is true in the digital republic we now inhabit.
To counter the digital manipulations that ever more clearly disadvantage the poor, the authors of the article in the Washington University Law Review call for "algorithmic accountability."
I just say, "good luck!"
If we don't want a government of, by, and for the algorithm, we are going to have to return to a politics based on real contact with real people.
In the flesh. Door to door.
When big data has to compete against a real person, big data dies!