Cyber-security and computer experts from the government and law enforcement are increasingly concerned with malicious code that runs on Linux and Apple Computer’s Mac OS X operating systems and threats posed by devices such as iPods and Xboxes. Intensive courses on the Mac OS X and Linux operating systems, as well as iPods, were just a few of the offerings at a recent cyber-security conference sponsored by the U.S. Department of Defense. Network administrators and cyber-investigators say they are increasingly being called on to investigate compromises of non-Windows operating systems and to analyze portable devices such as iPods.