Internet-age entrepreneurs make millions collecting and re-selling data about us, much of it from personal information we post online or give up in exchange for airline miles or hotel perks. Journalist Adam Tanner traces data mining to Caesar’s Entertainment and its Total Rewards program, which tracks every detail of players’ time in its casinos. Tanner is the author of "What Stays in Vegas: The World of Personal Data -- Lifeblood of Big Business -- and the End of Privacy as We Know It."