Since the advent of the last decade, we have been awash in an ocean of data, but we have only just begun to chart the wind and tides, much less plumb the depths.

Christian Rudder's Dataclysm offers a few sharp insights into the power of Big Data both to analyse us in the aggregate and profile us on a personal level. Rudder's focus, mercifully for us, is on the aggregate, but whether we are gay or straight, pregnant or not, sexually active or celibate, or in the market for anything at al, we cannot hide our digitized identity.

The main focus of Rudder's book, however, is on what Big Data can tell about ourselves as a people not ourselves as persons, whether it's age preferences of men and women looking for dates, racial biases in the evaluation of attraction, disease trends, or pharmaceutical dangers. Even as Rudder celebrates the power of data to reveal truths about us hitherto inaccessible to the most sophisticated pollster, an undercurrent of anxiety about the manipulative power of large organizations in a world without privacy runs through the book. But now that we are all at sea, we must navigate as best we can.