In 1973, four Swedes held in a bank vault for six days during a robbery became attached to their captors, a phenomenon dubbed the Stockholm Syndrome. According to psychologists, the abused bond to their abusers as a means to endure violence. The most notorious instance came when heiress Patty Hearst was kidnapped by the Symbionese Liberation Army, and after some months, re-christened herself "Tanya" and joined their ranks. "Get down or I'll blow your motherfucking heads off," she shouted while robbing a San Francisco bank with fellow S.L.A. members in April, 1974. The number one song in the U.S. that day was "Bennie and the Jets," by Elton John.