Does anything say so much about the times we live in as the fact that the word sharing has almost everything to do with personal information and almost nothing to do with personal wealth?

Of course, some will answer that we live in times when information is wealth. Generally these are people who have good teeth and drive nice cars. When they sit down to eat, which they do regularly and well, you can bet they’re not eating information.

To say the same thing in slightly different words: You and I belong to a society in which the gap between the rich and the poor is widening even as our personal privacy shrinks. It is the contention of this book that these two phenomena are connected, and connected in a number of ways.

To state just one of those ways: We tend to think of our right to privacy as a value that came about with the historical growth of the middle class. If, as current indices of income suggest, the middle class is vanishing, then it should come as no surprise if the privacy of all but a few people is vanishing with it.

This book also contends that privacy is important and worthy of preservation. It is important and worthy of preservation for the simple reason that human beings are important and worthy of preservation. These may seem like rather obvious statements, though if they were that obvious or universally believed we would not be so easily resigned to losing our privacy and to watching so many of our fellow human beings fall further and further behind in health, in education, in political power, and in privacy.

That privacy is a good thing for human beings is not hard to establish. Were it not a good thing, the wealthier among us would not enjoy more of it than the less wealthy do. The best things in life may be free, but that seldom prevents those at the top of the food chain from appropriating a lion’s share of the best things. Air is free, but it tends to smell better in Malibu than in East L.A.