The article focuses on system trustworthiness. It is a logical basis for confidence that a system will predictably satisfy its critical requirements, including information security, reliability, human safety, fault tolerance and survivability in the face of wide ranges of adversities. Critical national infrastructures depend in varying degrees on the dependable behavior of computer-communication resources, including the Internet and many of its attached computer systems. Their critical importance is generally underappreciated until something goes fundamentally wrong. Problems can result from natural circumstances, equipment failures, human errors, malicious activity, or a combination of these and other factors. Up-front preventive measures can result in significant savings and increases in human well-being, ameliorating major problems later on. Commercial considerations tend to trump human well-being, with business models sometimes considering protection of public welfare to be detrimental to corporate and enterprise bottom lines.