The controversy over President Bush's warrantless surveillance program took another surprise turn last week when a team of FBI agents, armed with a classified search warrant, raided the suburban Washington home of a former Justice Department lawyer. The lawyer, Thomas M. Tamm, previously worked in Justice's Office of Intelligence Policy and Review (OIPR)—the supersecret unit that oversees surveillance of terrorist and espionage targets. The agents seized Tamm's desktop computer, two of his children's laptops and a cache of personal files. Tamm and his lawyer, Paul Kemp, declined any comment. So did the FBI. But two legal sources who asked not...