This YouTube clip from the Andy Griffith Show is the sort of civics lesson that Attorney General Alberto Gonzales would do well to study. Guilherme Roschke from the Electronic Privacy Information Center (EPIC) has some background (via BoingBoing):
I shared the video with my colleagues here at the Electronic Privacy Information Center. With some digging, one of my colleagues figured out that this show aired on October 30, 1967. That's two weeks after the Supreme Court heard the oral arguments in Katz vs. United States. The FBI had tapped a phone booth without a warrant, and convicted a gambler based on that. The Katz court overturned the conviction, stating that the 4th amendment prohibits this sort of a wiretap without a warrant.