Most Internet users are familiar with trolling--aggressive, foul-mouthed posts designed to elicit angry responses in a site's comments. Less familiar but far more serious is the way some use networked technologies to target real people, subjecting them, by name and address, to vicious, often terrifying, online abuse. In an in-depth investigation of a problem that is too often trivialized by lawmakers and the media, Danielle Keats Citron exposes the...