RIM faces new U.S. fight over patents

Research In Motion Ltd. finds itself in a new patent infringement battle that could threaten its BlackBerry wireless service in the United States, less than two months after the company paid one of the biggest settlements in history to avoid an injunction there. Visto Corp., a well-funded Silicon Valley software company, claims RIM has willfully infringed on four of its patents used in the wireless transmission of e-mail and other data. Visto is asking a Texas court to ban all BlackBerry products and services in the U.S. and to award unspecified damages.