NSANSAIt's not a radical idea to limit surveillance to individuals who are actually being investigated. In fact, writes Steve Chapman, the Fourth Amendment to the Constitution -- no "unreasonable searches and seizures" -- has always meant the authorities couldn't ransack your home or your papers without a reason to think you've done something wrong. The administration takes the opposite approach. It insists it has to monitor millions of people continuously to find the few who are actually dangerous.