Tech-savvy employees can be a great boon to an enterprise, but they can create some daunting challenges for the IT department when they use personal devices or social networking sites on the job. The global health service company Cigna Corp. does not allow employees to use personal devices at work, but it is making substantial use of social media, according to Craig Shumard, chief information security officer. In an interview with FierceCIO, Shumard discusses the business value of social media as well as the security challenges it presents. FierceCIO