A German court overturned the conviction of a man who was found guilty of purchasing stolen goods over eBay in a case which may have hurt the online auctioneer's business in its top market after the United States. A state court in the southwestern city of Karlsruhe ruled in favor of the 47-year-old software engineer because he had not known that a car navigation system he bought over eBay two years ago had been stolen, a spokesman for the court said.