A Rhode Island couple whose son is accused of illegally sharing songs online should not be forced to surrender their home computer for inspection because it would violate their privacy, their lawyer argued at a federal court hearing. Joel Tenenbaum, a 25-year-old Boston University graduate student, is accused by the Recording Industry Association of America of downloading at least seven songs and making 816 music files available for distribution on the Kazaa file-sharing network through 2004.