Book excerpt: Who among us hasn't eavesdropped on a stranger's conversation in a theater or restaurant? Indeed, scientists have found that even animals eavesdrop on the calls and cries of others. In Eavesdropping, John L. Locke provides the first serious look at this virtually universal phenomenon. Locke's entertaining and disturbing account explores everything from sixteenth-century voyeurism to Hitchcock's "Rear Window"; from chimpanzee behavior to Parisian cafe society; from private eyes to Facebook and Twitter. He uncovers the biological drive behind the behavior and highlights its consequences across history and cultures. Eavesdropping can be a good thing--an attempt to understand what goes on in the lives of others so as to know better how to live one's own. Even birds who listen in on the calls of distant animals tend to survive longer. But Locke also concedes that eavesdropping has a bad name. It can encompass cheating to get unfair advantage, espionage to uncover secrets, and secretly monitoring emails to maintain power over employees. In the age of CCTV, phone tapping, and computer hacking, this is eye-opening reading. "