A network failure caused Research in Motion’s second large BlackBerry e-mail blackout in 10 months. About 8 million customers on all U.S. carriers were affected. Such service interruptions risk pushing BlackBerry users to a growing number of rival handheld e-mail devices, analysts say.“If they weren’t goaded into action last time, there’s no question that IT managers are going to be looking for alternatives now,” said Avi Greengart at Current Analysis Inc. (Bloomberg)