To experience a profound violation of your privacy, you need not opt for the "touch my junk" line at the airport. Just go online. There, sophisticated marketing and research companies are giving you the full WikiLeaks treatment through cookies, beacons, and other tracking devices that record your every move, like unseen spies. Somewhere, someone has made a record of your e-mail address, Facebook ID number, and even your name; they can record your every keystroke on the Web; they can sniff out information about health problems, interests, and attitudes, and sell that information to life-insurance companies, advertisers, or potential employers. Did you Google Viagra? Click on ads for weight-loss products? Someone knows. All of these intrusions are laid bare in an ongoing and superb Wall Street Journal series called "What They Know.'' The series deserves a Pulitzer, for revealing the extent to which companies are secretly compiling detailed profiles of your likes, dislikes, purchases, searches, sexual proclivities, and religious and political beliefs.

There's a curious paradox involved in communicating and gathering information via a keyboard and a computer. It feels so intimate and personal, but is utterly not; it's called the World Wide Web for a reason. Your e-mails can be retrieved and used in lawsuits, and are screened by the government for evidence of violent intent. A hacker on another continent can seize control of your hard drive. An Army private can plunder the government's "private" network, embarrassing diplomats, presidents, and kings. Here’s your Miranda warning: You have a right to remain silent, but whatever you do online can and will be held against you.