PARKER:

Well, not only that you hand in an e-mail address or a campaign will have a little bit of code on their Web site where they track you, and they can see when you came to their Web site, you clicked the donation page and maybe gave a donation, or maybe you sort of learned a bit more about the candidate and visited the candidate's energy page so they know you're interested in energy.

So, they have your e-mail address. They have this other information about you and then they can literally sort of follow you over to Facebook and they can know that you, specific user, who has this e-mail address and who cares about energy is also on Facebook, and they can also then overlay Facebook's data.

So, maybe Facebook knows that in addition to those things, you watch FOX News a lot and you went to a certain college and you live in a certain state like Iowa or New Hampshire.

And then they can target you with a very specific ad, knowing that you're likely an Iowa caucus-goer who cares energy and watches FOX News and is friends with these people. And you sort of get this ad in your stream and it's directed exactly to you and your interests.