Introduction -- Defining big data -- Smartphones as an example of how big data and privacy intersect -- The competitive significance of big data -- Why haven't market forces addressed consumers' privacy concerns? -- The US's and EU's mixed record in assessing data-driven mergers -- Agencies focus on what is measurable (Price), which is not always important (Free Goods) -- Data-driven mergers often fall outside competition policy's conventional categories -- Belief that privacy concerns differ from competition policy objectives -- Importance of entry barriers in antitrust analysis -- Entry barriers can be higher in multi-sided markets, where one side exhibits traditional network effects -- Scale of data : trial-and-error, 'Learning-by-doing' network effects -- Two more network effects : scope of data and spill-over effects -- Reflections on data-driven network effects -- Risk of inadequate merger enforcement -- The price of weak antitrust enforcement -- Recognizing when privacy and competition law intersect -- Data-opoly : identifying data-driven exclusionary and predatory conduct -- Understanding and assessing data-drien efficiencies claims -- Need for retrospectives of data-driven mergers -- More coordination among competition, privacy, and consumer protection officials.