WASHINGTON - When the Supreme Court justices were growing up, swapping music meant exchanging vinyl records. And sharing a movie involved walking someone to the cinema. Today many of the latest hit songs and movies are a few mouse clicks away on the Internet, and those same justices are being asked to settle a multibillion-dollar dispute about how such items are shared. Entertainment companies want the court to let them sue the manufacturers of file-sharing software that allows computer users to download music and movies from each other's computers. The companies say such downloads violate copyright protections and amount to...